642257 has 16 divisors (see below), whose sum is σ = 844800. Its totient is φ = 473040.

The previous prime is 642253. The next prime is 642281. The reversal of 642257 is 752246.

642257 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 642257 - 2² = 642253 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 642257.

It is not an unprimeable number, because it can be changed into a prime (642253) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1244 + ... + 1682.

It is an arithmetic number, because the mean of its divisors is an integer number (52800).

2⁶⁴²²⁵⁷ is an apocalyptic number.

It is an amenable number.

642257 is a deficient number, since it is larger than the sum of its proper divisors (202543).

642257 is a wasteful number, since it uses less digits than its factorization.

642257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 476.

The product of its digits is 3360, while the sum is 26.

The square root of 642257 is about 801.4093835238. The cubic root of 642257 is about 86.2785720644.

The spelling of 642257 in words is "six hundred forty-two thousand, two hundred fifty-seven".