221371372656 has 320 divisors, whose sum is σ = 752056151040. Its totient is φ = 61035586560.

The previous prime is 221371372639. The next prime is 221371372679. The reversal of 221371372656 is 656273173122.

221371372656 is a `hidden beast` number, since 2 + 213 + 7 + 1 + 372 + 65 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9765271 + ... + 9787913.

It is an arithmetic number, because the mean of its divisors is an integer number (2350175472).

Almost surely, 2^221371372656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221371372656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (376028075520).

221371372656 is an abundant number, since it is smaller than the sum of its proper divisors (530684778384).

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

221371372656 is a wasteful number, since it uses less digits than its factorization.

221371372656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22781 (or 22769 counting only the distinct ones).

The product of its digits is 635040, while the sum is 45.

The spelling of 221371372656 in words is "two hundred twenty-one billion, three hundred seventy-one million, three hundred seventy-two thousand, six hundred fifty-six".