257045021 has 4 divisors (see below), whose sum is σ = 262514112. Its totient is φ = 251575932.

The previous prime is 257045011. The next prime is 257045023. The reversal of 257045021 is 120540752.

257045021 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257045021 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 (257045023) 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, 2734475 + ... + 2734568.

It is an arithmetic number, because the mean of its divisors is an integer number (65628528).

Almost surely, 2^257045021 is an apocalyptic number.

It is an amenable number.

257045021 is a deficient number, since it is larger than the sum of its proper divisors (5469091).

257045021 is an equidigital number, since it uses as much as digits as its factorization.

257045021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5469090.

The product of its (nonzero) digits is 2800, while the sum is 26.

The square root of 257045021 is about 16032.6236468022. The cubic root of 257045021 is about 635.8232412621.

Adding to 257045021 its reverse (120540752), we get a palindrome (377585773).

The spelling of 257045021 in words is "two hundred fifty-seven million, forty-five thousand, twenty-one".