216636680 has 128 divisors (see below), whose sum is σ = 551577600. Its totient is φ = 76032000.

The previous prime is 216636671. The next prime is 216636683. The reversal of 216636680 is 86636612.

It is a super-2 number, since 2×216636680² = 93862902242844800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (216636683) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 1434605 + ... + 1434755.

It is an arithmetic number, because the mean of its divisors is an integer number (4309200).

Almost surely, 2^216636680 is an apocalyptic number.

216636680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216636680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (275788800).

216636680 is an abundant number, since it is smaller than the sum of its proper divisors (334940920).

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

216636680 is a wasteful number, since it uses less digits than its factorization.

216636680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295 (or 291 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 38.

The square root of 216636680 is about 14718.5828122140. The cubic root of 216636680 is about 600.5889402450.

The spelling of 216636680 in words is "two hundred sixteen million, six hundred thirty-six thousand, six hundred eighty".