221865996 has 24 divisors (see below), whose sum is σ = 564750144. Its totient is φ = 67232080.

The previous prime is 221865989. The next prime is 221866033. The reversal of 221865996 is 699568122.

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, 840270 + ... + 840533.

It is an arithmetic number, because the mean of its divisors is an integer number (23531256).

Almost surely, 2^221865996 is an apocalyptic number.

It is an amenable number.

221865996 is an abundant number, since it is smaller than the sum of its proper divisors (342884148).

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

221865996 is a wasteful number, since it uses less digits than its factorization.

221865996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1680821 (or 1680819 counting only the distinct ones).

The product of its digits is 466560, while the sum is 48.

The square root of 221865996 is about 14895.1668671418. The cubic root of 221865996 is about 605.3830381806.

It can be divided in two parts, 22186 and 5996, that added together give a palindrome (28182).

The spelling of 221865996 in words is "two hundred twenty-one million, eight hundred sixty-five thousand, nine hundred ninety-six".