256531658 has 4 divisors (see below), whose sum is σ = 384797490. Its totient is φ = 128265828.

The previous prime is 256531637. The next prime is 256531663. The reversal of 256531658 is 856135652.

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

It can be written as a sum of positive squares in only one way, i.e., 255456289 + 1075369 = 15983^2 + 1037^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64132913 + ... + 64132916.

Almost surely, 2^256531658 is an apocalyptic number.

256531658 is a deficient number, since it is larger than the sum of its proper divisors (128265832).

256531658 is a wasteful number, since it uses less digits than its factorization.

256531658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128265831.

The product of its digits is 216000, while the sum is 41.

The square root of 256531658 is about 16016.6056953401. The cubic root of 256531658 is about 635.3996764660.

The spelling of 256531658 in words is "two hundred fifty-six million, five hundred thirty-one thousand, six hundred fifty-eight".