221390976 has 32 divisors (see below), whose sum is σ = 588070800. Its totient is φ = 73796864.

The previous prime is 221390947. The next prime is 221390977. The reversal of 221390976 is 679093122.

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (221390977) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 287886 + ... + 288653.

Almost surely, 2^221390976 is an apocalyptic number.

It is an amenable number.

221390976 is an abundant number, since it is smaller than the sum of its proper divisors (366679824).

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

221390976 is an equidigital number, since it uses as much as digits as its factorization.

221390976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 576556 (or 576544 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 39.

The square root of 221390976 is about 14879.2128824075. The cubic root of 221390976 is about 604.9506833193.

The spelling of 221390976 in words is "two hundred twenty-one million, three hundred ninety thousand, nine hundred seventy-six".