221660992 has 56 divisors (see below), whose sum is σ = 529173440. Its totient is φ = 89994240.

The previous prime is 221660987. The next prime is 221660993. The reversal of 221660992 is 299066122.

It is a tau number, because it is divible by the number of its divisors (56).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221660993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4509 + ... + 21532.

Almost surely, 2^221660992 is an apocalyptic number.

It is an amenable number.

221660992 is an abundant number, since it is smaller than the sum of its proper divisors (307512448).

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

221660992 is a wasteful number, since it uses less digits than its factorization.

221660992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26079 (or 26069 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 221660992 is about 14888.2837157276. The cubic root of 221660992 is about 605.1965229104.

The spelling of 221660992 in words is "two hundred twenty-one million, six hundred sixty thousand, nine hundred ninety-two".