Fiftyseven

Fifty-seven, or 57, is the integer that follows fifty-six and precedes fifty-eight. In numerals it is 57 and in Roman numerals LVII. In base-2 (binary) it is 111001 and in hexadecimal it is 0x39.

In mathematics, 57 is an odd composite number and the product of the primes 3 and 19, making it a semiprime and squarefree. Its divisors are 1, 3, 19, and 57. The digits 5 and 7 sum to 12, and 57 is divisible by 3.

In science, 57 is the atomic number of lanthanum, a soft, silvery-white metal and the first member of the lanthanide series. Lanthanum occurs in minerals such as monazite and bastnäsite and is used in various catalysts, glass additives, and certain battery technologies, including some nickel-metal hydride formulations.

In culture, Heinz's slogan "57 Varieties" is associated with the number 57, though Heinz notes that the number was chosen for marketing and not to indicate a precise product count. The number 57 also appears in various place names and media references, and has been used in the designations of highways such as I-57 in the United States.