256365551 has 8 divisors (see below), whose sum is σ = 276420144. Its totient is φ = 236358720.

The previous prime is 256365547. The next prime is 256365581. The reversal of 256365551 is 155563652.

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

It is not a de Polignac number, because 256365551 - 2² = 256365547 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256365581) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 365 + ... + 22646.

It is an arithmetic number, because the mean of its divisors is an integer number (34552518).

Almost surely, 2^256365551 is an apocalyptic number.

256365551 is a deficient number, since it is larger than the sum of its proper divisors (20054593).

256365551 is a wasteful number, since it uses less digits than its factorization.

256365551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23881.

The product of its digits is 135000, while the sum is 38.

The square root of 256365551 is about 16011.4193936703. The cubic root of 256365551 is about 635.2625041531.

The spelling of 256365551 in words is "two hundred fifty-six million, three hundred sixty-five thousand, five hundred fifty-one".