221616620 has 48 divisors (see below), whose sum is σ = 472644480. Its totient is φ = 87277824.

The previous prime is 221616601. The next prime is 221616623. The reversal of 221616620 is 26616122.

221616620 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×221616620² = 98227852520448800, 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 221616620.

It is not an unprimeable number, because it can be changed into a prime (221616623) 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, 603677 + ... + 604043.

It is an arithmetic number, because the mean of its divisors is an integer number (9846760).

Almost surely, 2^221616620 is an apocalyptic number.

221616620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221616620 is an abundant number, since it is smaller than the sum of its proper divisors (251027860).

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

221616620 is a wasteful number, since it uses less digits than its factorization.

221616620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 762 (or 760 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 221616620 is about 14886.7934760982. The cubic root of 221616620 is about 605.1561375575.

The spelling of 221616620 in words is "two hundred twenty-one million, six hundred sixteen thousand, six hundred twenty".