216939379531 has 24 divisors (see below), whose sum is σ = 260386747872. Its totient is φ = 176999385600.

The previous prime is 216939379523. The next prime is 216939379603. The reversal of 216939379531 is 135973939612.

It is a happy number.

It is not a de Polignac number, because 216939379531 - 2³ = 216939379523 is a prime.

It is a super-2 number, since 2×216939379531² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (216939371531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 146011 + ... + 674683.

It is an arithmetic number, because the mean of its divisors is an integer number (10849447828).

Almost surely, 2^216939379531 is an apocalyptic number.

216939379531 is a deficient number, since it is larger than the sum of its proper divisors (43447368341).

216939379531 is an equidigital number, since it uses as much as digits as its factorization.

216939379531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528803 (or 528772 counting only the distinct ones).

The product of its digits is 8266860, while the sum is 58.

The spelling of 216939379531 in words is "two hundred sixteen billion, nine hundred thirty-nine million, three hundred seventy-nine thousand, five hundred thirty-one".