256621366 has 8 divisors (see below), whose sum is σ = 385032384. Its totient is φ = 128277240.

The previous prime is 256621349. The next prime is 256621369. The reversal of 256621366 is 663126652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256621369) 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, 5670 + ... + 23353.

It is an arithmetic number, because the mean of its divisors is an integer number (48129048).

Almost surely, 2^256621366 is an apocalyptic number.

256621366 is a deficient number, since it is larger than the sum of its proper divisors (128411018).

256621366 is a wasteful number, since it uses less digits than its factorization.

256621366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33446.

The product of its digits is 77760, while the sum is 37.

The square root of 256621366 is about 16019.4059190720. The cubic root of 256621366 is about 635.4737333311.

It can be divided in two parts, 25662 and 1366, that added together give a triangular number (27028 = T₂₃₂).

The spelling of 256621366 in words is "two hundred fifty-six million, six hundred twenty-one thousand, three hundred sixty-six".