257430921 has 16 divisors (see below), whose sum is σ = 378157248. Its totient is φ = 154472000.

The previous prime is 257430907. The next prime is 257430931. The reversal of 257430921 is 129034752.

It is a cyclic number.

It is not a de Polignac number, because 257430921 - 2⁶ = 257430857 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (257430931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35286 + ... + 41951.

It is an arithmetic number, because the mean of its divisors is an integer number (23634828).

Almost surely, 2^257430921 is an apocalyptic number.

It is an amenable number.

257430921 is a deficient number, since it is larger than the sum of its proper divisors (120726327).

257430921 is a wasteful number, since it uses less digits than its factorization.

257430921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77352.

The product of its (nonzero) digits is 15120, while the sum is 33.

The square root of 257430921 is about 16044.6539694691. The cubic root of 257430921 is about 636.1412679153.

The spelling of 257430921 in words is "two hundred fifty-seven million, four hundred thirty thousand, nine hundred twenty-one".