256643597 has 8 divisors (see below), whose sum is σ = 295003776. Its totient is φ = 218707632.

The previous prime is 256643593. The next prime is 256643603. The reversal of 256643597 is 795346652.

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 256643597 - 2² = 256643593 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 (256643593) 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, 104753 + ... + 107174.

It is an arithmetic number, because the mean of its divisors is an integer number (36875472).

Almost surely, 2^256643597 is an apocalyptic number.

It is an amenable number.

256643597 is a deficient number, since it is larger than the sum of its proper divisors (38360179).

256643597 is a wasteful number, since it uses less digits than its factorization.

256643597 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212107.

The product of its digits is 1360800, while the sum is 47.

The square root of 256643597 is about 16020.0997812124. The cubic root of 256643597 is about 635.4920830745.

The spelling of 256643597 in words is "two hundred fifty-six million, six hundred forty-three thousand, five hundred ninety-seven".