256215634 has 4 divisors (see below), whose sum is σ = 384323454. Its totient is φ = 128107816.

The previous prime is 256215623. The next prime is 256215637. The reversal of 256215634 is 436512652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 213247609 + 42968025 = 14603^2 + 6555^2 .

It is a super-2 number, since 2×256215634² = 131292902212043912, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 256215634.

It is not an unprimeable number, because it can be changed into a prime (256215637) 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 as a sum of consecutive naturals, namely, 64053907 + ... + 64053910.

Almost surely, 2^256215634 is an apocalyptic number.

256215634 is a deficient number, since it is larger than the sum of its proper divisors (128107820).

256215634 is a wasteful number, since it uses less digits than its factorization.

256215634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128107819.

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

The square root of 256215634 is about 16006.7371440903. The cubic root of 256215634 is about 635.1386507744.

The spelling of 256215634 in words is "two hundred fifty-six million, two hundred fifteen thousand, six hundred thirty-four".