216531836858 has 16 divisors (see below), whose sum is σ = 348614516520. Its totient is φ = 100501479936.

The previous prime is 216531836849. The next prime is 216531836879. The reversal of 216531836858 is 858638135612.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 202916914369 + 13614922489 = 450463^2 + 116683^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43617953 + ... + 43622916.

Almost surely, 2^216531836858 is an apocalyptic number.

216531836858 is a deficient number, since it is larger than the sum of its proper divisors (132082679662).

216531836858 is a wasteful number, since it uses less digits than its factorization.

216531836858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87240961.

The product of its digits is 8294400, while the sum is 56.

The spelling of 216531836858 in words is "two hundred sixteen billion, five hundred thirty-one million, eight hundred thirty-six thousand, eight hundred fifty-eight".