256521603 has 32 divisors (see below), whose sum is σ = 391605760. Its totient is φ = 148055040.

The previous prime is 256521593. The next prime is 256521607. The reversal of 256521603 is 306125652.

256521603 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 256521603 - 2⁵ = 256521571 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256521607) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 74643 + ... + 78003.

It is an arithmetic number, because the mean of its divisors is an integer number (12237680).

Almost surely, 2^256521603 is an apocalyptic number.

256521603 is a deficient number, since it is larger than the sum of its proper divisors (135084157).

256521603 is a wasteful number, since it uses less digits than its factorization.

256521603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3499.

The product of its (nonzero) digits is 10800, while the sum is 30.

The square root of 256521603 is about 16016.2917992899. The cubic root of 256521603 is about 635.3913746612.

The spelling of 256521603 in words is "two hundred fifty-six million, five hundred twenty-one thousand, six hundred three".