256216531 has 8 divisors (see below), whose sum is σ = 262475264. Its totient is φ = 250024320.

The previous prime is 256216511. The next prime is 256216553. The reversal of 256216531 is 135612652.

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 256216531 - 2⁹ = 256216019 is a prime.

It is a super-2 number, since 2×256216531² = 131293821515347922, which contains 22 as substring.

It is a Duffinian number.

256216531 is a modest number, since divided by 16531 gives 2562 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 256216493 and 256216502.

It is not an unprimeable number, because it can be changed into a prime (256216511) 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, 8790 + ... + 24283.

It is an arithmetic number, because the mean of its divisors is an integer number (32809408).

Almost surely, 2^256216531 is an apocalyptic number.

256216531 is a deficient number, since it is larger than the sum of its proper divisors (6258733).

256216531 is a wasteful number, since it uses less digits than its factorization.

256216531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33261.

The product of its digits is 10800, while the sum is 31.

The square root of 256216531 is about 16006.7651635176. The cubic root of 256216531 is about 635.1393919713.

The spelling of 256216531 in words is "two hundred fifty-six million, two hundred sixteen thousand, five hundred thirty-one".