257902661 has 4 divisors (see below), whose sum is σ = 258420000. Its totient is φ = 257385324.

The previous prime is 257902651. The next prime is 257902679. The reversal of 257902661 is 166209752.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 257902661 - 2²⁶ = 190793797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257902651) 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, 257921 + ... + 258918.

It is an arithmetic number, because the mean of its divisors is an integer number (64605000).

Almost surely, 2^257902661 is an apocalyptic number.

It is an amenable number.

257902661 is a deficient number, since it is larger than the sum of its proper divisors (517339).

257902661 is an equidigital number, since it uses as much as digits as its factorization.

257902661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517338.

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 257902661 is about 16059.3480876404. The cubic root of 257902661 is about 636.5296053131.

The spelling of 257902661 in words is "two hundred fifty-seven million, nine hundred two thousand, six hundred sixty-one".