256521436 has 6 divisors (see below), whose sum is σ = 448912520. Its totient is φ = 128260716.

The previous prime is 256521427. The next prime is 256521469. The reversal of 256521436 is 634125652.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32065176 + ... + 32065183.

Almost surely, 2^256521436 is an apocalyptic number.

It is an amenable number.

256521436 is a deficient number, since it is larger than the sum of its proper divisors (192391084).

256521436 is a wasteful number, since it uses less digits than its factorization.

256521436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64130363 (or 64130361 counting only the distinct ones).

The product of its digits is 43200, while the sum is 34.

The square root of 256521436 is about 16016.2865858475. The cubic root of 256521436 is about 635.3912367776.

The spelling of 256521436 in words is "two hundred fifty-six million, five hundred twenty-one thousand, four hundred thirty-six".