256861658 has 8 divisors (see below), whose sum is σ = 387020928. Its totient is φ = 127854684.

The previous prime is 256861639. The next prime is 256861727. The reversal of 256861658 is 856168652.

It is a happy number.

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

It is a super-2 number, since 2×256861658² = 131955822701017928, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 287516 + ... + 288407.

It is an arithmetic number, because the mean of its divisors is an integer number (48377616).

Almost surely, 2^256861658 is an apocalyptic number.

256861658 is a deficient number, since it is larger than the sum of its proper divisors (130159270).

256861658 is a wasteful number, since it uses less digits than its factorization.

256861658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576148.

The product of its digits is 691200, while the sum is 47.

The square root of 256861658 is about 16026.9041926381. The cubic root of 256861658 is about 635.6720171823.

The spelling of 256861658 in words is "two hundred fifty-six million, eight hundred sixty-one thousand, six hundred fifty-eight".