256966009 has 8 divisors (see below), whose sum is σ = 258789960. Its totient is φ = 255148800.

The previous prime is 256966007. The next prime is 256966027. The reversal of 256966009 is 900669652.

It can be written as a sum of positive squares in 4 ways, for example, as 19713600 + 237252409 = 4440^2 + 15403^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 256966009 - 2¹ = 256966007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256966007) 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, 92379 + ... + 95119.

It is an arithmetic number, because the mean of its divisors is an integer number (32348745).

Almost surely, 2^256966009 is an apocalyptic number.

It is an amenable number.

256966009 is a deficient number, since it is larger than the sum of its proper divisors (1823951).

256966009 is a wasteful number, since it uses less digits than its factorization.

256966009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3371.

The product of its (nonzero) digits is 174960, while the sum is 43.

The square root of 256966009 is about 16030.1593566627. The cubic root of 256966009 is about 635.7580868985.

The spelling of 256966009 in words is "two hundred fifty-six million, nine hundred sixty-six thousand, nine".