216831966 has 32 divisors (see below), whose sum is σ = 474004608. Its totient is φ = 65720160.

The previous prime is 216831961. The next prime is 216831977. The reversal of 216831966 is 669138612.

It is a super-2 number, since 2×216831966² = 94032202958850312, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216831961) 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, 15520 + ... + 25971.

It is an arithmetic number, because the mean of its divisors is an integer number (14812644).

Almost surely, 2^216831966 is an apocalyptic number.

216831966 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

216831966 is an abundant number, since it is smaller than the sum of its proper divisors (257172642).

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

216831966 is a wasteful number, since it uses less digits than its factorization.

216831966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41576.

The product of its digits is 93312, while the sum is 42.

The square root of 216831966 is about 14725.2153125175. The cubic root of 216831966 is about 600.7693519632.

The spelling of 216831966 in words is "two hundred sixteen million, eight hundred thirty-one thousand, nine hundred sixty-six".