256376909 has 4 divisors (see below), whose sum is σ = 256585404. Its totient is φ = 256168416.

The previous prime is 256376903. The next prime is 256376921. The reversal of 256376909 is 909673652.

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

It can be written as a sum of positive squares in 2 ways, for example, as 186186025 + 70190884 = 13645^2 + 8378^2 .

It is a cyclic number.

It is not a de Polignac number, because 256376909 - 2²⁴ = 239599693 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 (256376903) 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, 102392 + ... + 104865.

It is an arithmetic number, because the mean of its divisors is an integer number (64146351).

Almost surely, 2^256376909 is an apocalyptic number.

It is an amenable number.

256376909 is a deficient number, since it is larger than the sum of its proper divisors (208495).

256376909 is a wasteful number, since it uses less digits than its factorization.

256376909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208494.

The product of its (nonzero) digits is 612360, while the sum is 47.

The square root of 256376909 is about 16011.7740740993. The cubic root of 256376909 is about 635.2718855552.

The spelling of 256376909 in words is "two hundred fifty-six million, three hundred seventy-six thousand, nine hundred nine".