221616522 has 48 divisors (see below), whose sum is σ = 509862600. Its totient is φ = 69328896.

The previous prime is 221616487. The next prime is 221616533. The reversal of 221616522 is 225616122.

221616522 is a `hidden beast` number, since 2 + 2 + 1 + 6 + 1 + 652 + 2 = 666.

221616522 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 218123361 + 3493161 = 14769^2 + 1869^2 .

It is a super-2 number, since 2×221616522² = 98227765646752968, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 136588 + ... + 138200.

Almost surely, 2^221616522 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221616522, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (254931300).

221616522 is an abundant number, since it is smaller than the sum of its proper divisors (288246078).

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

221616522 is a wasteful number, since it uses less digits than its factorization.

221616522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2087 (or 2084 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 221616522 is about 14886.7901845898. The cubic root of 221616522 is about 605.1560483564.

The spelling of 221616522 in words is "two hundred twenty-one million, six hundred sixteen thousand, five hundred twenty-two".