221991662134620 has 432 divisors, whose sum is σ = 786139812345888. Its totient is φ = 50557983114240.

The previous prime is 221991662134607. The next prime is 221991662134717. The reversal of 221991662134620 is 26431266199122.

221991662134620 is a `hidden beast` number, since 2 + 2 + 1 + 9 + 9 + 1 + 6 + 6 + 2 + 1 + 3 + 4 + 620 = 666.

221991662134620 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 8721617814 + ... + 8721643266.

It is an arithmetic number, because the mean of its divisors is an integer number (1819768084134).

Almost surely, 2^{221991662134620} is an apocalyptic number.

221991662134620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221991662134620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (393069906172944).

221991662134620 is an abundant number, since it is smaller than the sum of its proper divisors (564148150211268).

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

221991662134620 is a wasteful number, since it uses less digits than its factorization.

221991662134620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29010 (or 28998 counting only the distinct ones).

The product of its (nonzero) digits is 3359232, while the sum is 54.

The spelling of 221991662134620 in words is "two hundred twenty-one trillion, nine hundred ninety-one billion, six hundred sixty-two million, one hundred thirty-four thousand, six hundred twenty".