216831972 has 96 divisors (see below), whose sum is σ = 596800512. Its totient is φ = 59988096.

The previous prime is 216831961. The next prime is 216831977. The reversal of 216831972 is 279138612.

It is a super-2 number, since 2×216831972² = 94032208162817568, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 216831972.

It is not an unprimeable number, because it can be changed into a prime (216831977) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 624703 + ... + 625049.

It is an arithmetic number, because the mean of its divisors is an integer number (6216672).

Almost surely, 2^216831972 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216831972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (298400256).

216831972 is an abundant number, since it is smaller than the sum of its proper divisors (379968540).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

216831972 is a wasteful number, since it uses less digits than its factorization.

216831972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 577 (or 575 counting only the distinct ones).

The product of its digits is 36288, while the sum is 39.

The square root of 216831972 is about 14725.2155162497. The cubic root of 216831972 is about 600.7693575045.

The spelling of 216831972 in words is "two hundred sixteen million, eight hundred thirty-one thousand, nine hundred seventy-two".