256551501 has 4 divisors (see below), whose sum is σ = 342068672. Its totient is φ = 171034332.

The previous prime is 256551497. The next prime is 256551527. The reversal of 256551501 is 105155652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 256551501 - 2² = 256551497 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256551551) 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, 42758581 + ... + 42758586.

It is an arithmetic number, because the mean of its divisors is an integer number (85517168).

Almost surely, 2^256551501 is an apocalyptic number.

It is an amenable number.

256551501 is a deficient number, since it is larger than the sum of its proper divisors (85517171).

256551501 is an equidigital number, since it uses as much as digits as its factorization.

256551501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85517170.

The product of its (nonzero) digits is 7500, while the sum is 30.

The square root of 256551501 is about 16017.2251342110. The cubic root of 256551501 is about 635.4160589934.

The spelling of 256551501 in words is "two hundred fifty-six million, five hundred fifty-one thousand, five hundred one".