221365437656 has 32 divisors (see below), whose sum is σ = 463836678480. Its totient is φ = 98166489600.

The previous prime is 221365437649. The next prime is 221365437677. The reversal of 221365437656 is 656734563122.

It is a congruent number.

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, 30673421 + ... + 30680636.

Almost surely, 2^221365437656 is an apocalyptic number.

It is an amenable number.

221365437656 is an abundant number, since it is smaller than the sum of its proper divisors (242471240824).

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

221365437656 is a wasteful number, since it uses less digits than its factorization.

221365437656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61354115 (or 61354111 counting only the distinct ones).

The product of its digits is 5443200, while the sum is 50.

The spelling of 221365437656 in words is "two hundred twenty-one billion, three hundred sixty-five million, four hundred thirty-seven thousand, six hundred fifty-six".