216556520 has 32 divisors (see below), whose sum is σ = 487710720. Its totient is φ = 86541120.

The previous prime is 216556517. The next prime is 216556553. The reversal of 216556520 is 25655612.

216556520 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58649 + ... + 62231.

It is an arithmetic number, because the mean of its divisors is an integer number (15240960).

Almost surely, 2^216556520 is an apocalyptic number.

216556520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

216556520 is an abundant number, since it is smaller than the sum of its proper divisors (271154200).

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

216556520 is a wasteful number, since it uses less digits than its factorization.

216556520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5105 (or 5101 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 32.

The square root of 216556520 is about 14715.8594720118. The cubic root of 216556520 is about 600.5148543782.

It can be divided in two parts, 2165 and 56520, that added together give a palindrome (58685).

The spelling of 216556520 in words is "two hundred sixteen million, five hundred fifty-six thousand, five hundred twenty".