221616990 has 48 divisors (see below), whose sum is σ = 658520928. Its totient is φ = 50655168.

The previous prime is 221616973. The next prime is 221617021. The reversal of 221616990 is 99616122.

It is a super-2 number, since 2×221616990² = 98228180513320200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 175257 + ... + 176516.

It is an arithmetic number, because the mean of its divisors is an integer number (13719186).

Almost surely, 2^221616990 is an apocalyptic number.

221616990 is an abundant number, since it is smaller than the sum of its proper divisors (436903938).

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

221616990 is a wasteful number, since it uses less digits than its factorization.

221616990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351793 (or 351790 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 221616990 is about 14886.8059032151. The cubic root of 221616990 is about 605.1564743367.

The spelling of 221616990 in words is "two hundred twenty-one million, six hundred sixteen thousand, nine hundred ninety".