221279864 has 16 divisors (see below), whose sum is σ = 446815320. Its totient is φ = 102129120.

The previous prime is 221279813. The next prime is 221279881. The reversal of 221279864 is 468972122.

221279864 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1063742 + ... + 1063949.

Almost surely, 2^221279864 is an apocalyptic number.

It is an amenable number.

221279864 is an abundant number, since it is smaller than the sum of its proper divisors (225535456).

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

221279864 is a wasteful number, since it uses less digits than its factorization.

221279864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2127710 (or 2127706 counting only the distinct ones).

The product of its digits is 96768, while the sum is 41.

The square root of 221279864 is about 14875.4786141489. The cubic root of 221279864 is about 604.8494618969.

The spelling of 221279864 in words is "two hundred twenty-one million, two hundred seventy-nine thousand, eight hundred sixty-four".