257642563 has 4 divisors (see below), whose sum is σ = 257696208. Its totient is φ = 257588920.

The previous prime is 257642549. The next prime is 257642639. The reversal of 257642563 is 365246752.

257642563 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257642563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (257642513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18823 + ... + 29488.

It is an arithmetic number, because the mean of its divisors is an integer number (64424052).

Almost surely, 2^257642563 is an apocalyptic number.

257642563 is a deficient number, since it is larger than the sum of its proper divisors (53645).

257642563 is an equidigital number, since it uses as much as digits as its factorization.

257642563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53644.

The product of its digits is 302400, while the sum is 40.

The square root of 257642563 is about 16051.2480200139. The cubic root of 257642563 is about 636.3155506974.

The spelling of 257642563 in words is "two hundred fifty-seven million, six hundred forty-two thousand, five hundred sixty-three".