256520403 has 12 divisors (see below), whose sum is σ = 386639760. Its totient is φ = 163578096.

The previous prime is 256520333. The next prime is 256520417. The reversal of 256520403 is 304025652.

256520403 is a `hidden beast` number, since 2 + 5 + 652 + 0 + 4 + 0 + 3 = 666.

256520403 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 256520403 - 2¹² = 256516307 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256520423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 619408 + ... + 619821.

It is an arithmetic number, because the mean of its divisors is an integer number (32219980).

Almost surely, 2^256520403 is an apocalyptic number.

256520403 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

256520403 is a deficient number, since it is larger than the sum of its proper divisors (130119357).

256520403 is a wasteful number, since it uses less digits than its factorization.

256520403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1239258 (or 1239255 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 27.

The square root of 256520403 is about 16016.2543373911. The cubic root of 256520403 is about 635.3903838794.

The spelling of 256520403 in words is "two hundred fifty-six million, five hundred twenty thousand, four hundred three".