216812631 has 16 divisors (see below), whose sum is σ = 333592064. Its totient is φ = 122688864.

The previous prime is 216812623. The next prime is 216812639. The reversal of 216812631 is 136218612.

It is an interprime number because it is at equal distance from previous prime (216812623) and next prime (216812639).

It is not a de Polignac number, because 216812631 - 2³ = 216812623 is a prime.

It is a super-2 number, since 2×216812631² = 94015433922284322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216812639) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47956 + ... + 52281.

It is an arithmetic number, because the mean of its divisors is an integer number (20849504).

Almost surely, 2^216812631 is an apocalyptic number.

216812631 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

216812631 is a deficient number, since it is larger than the sum of its proper divisors (116779433).

216812631 is a wasteful number, since it uses less digits than its factorization.

216812631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100350.

The product of its digits is 3456, while the sum is 30.

The square root of 216812631 is about 14724.5587709785. The cubic root of 216812631 is about 600.7514944782.

The spelling of 216812631 in words is "two hundred sixteen million, eight hundred twelve thousand, six hundred thirty-one".