216992780 has 12 divisors (see below), whose sum is σ = 455684880. Its totient is φ = 86797104.

The previous prime is 216992773. The next prime is 216992791. The reversal of 216992780 is 87299612.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5424800 + ... + 5424839.

It is an arithmetic number, because the mean of its divisors is an integer number (37973740).

Almost surely, 2^216992780 is an apocalyptic number.

216992780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

216992780 is an abundant number, since it is smaller than the sum of its proper divisors (238692100).

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

216992780 is a wasteful number, since it uses less digits than its factorization.

216992780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10849648 (or 10849646 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 216992780 is about 14730.6747978496. The cubic root of 216992780 is about 600.9178359866.

It can be divided in two parts, 2169 and 92780, that added together give a palindrome (94949).

The spelling of 216992780 in words is "two hundred sixteen million, nine hundred ninety-two thousand, seven hundred eighty".