256188551 has 4 divisors (see below), whose sum is σ = 256227672. Its totient is φ = 256149432.

The previous prime is 256188511. The next prime is 256188613. The reversal of 256188551 is 155881652.

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

It is a cyclic number.

It is not a de Polignac number, because 256188551 - 2¹⁰ = 256187527 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 256188499 and 256188508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256188511) 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, 7085 + ... + 23718.

It is an arithmetic number, because the mean of its divisors is an integer number (64056918).

Almost surely, 2^256188551 is an apocalyptic number.

256188551 is a deficient number, since it is larger than the sum of its proper divisors (39121).

256188551 is an equidigital number, since it uses as much as digits as its factorization.

256188551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39120.

The product of its digits is 96000, while the sum is 41.

The square root of 256188551 is about 16005.8911342043. The cubic root of 256188551 is about 635.1162711016.

The spelling of 256188551 in words is "two hundred fifty-six million, one hundred eighty-eight thousand, five hundred fifty-one".