221607601920 has 1008 divisors, whose sum is σ = 844165066752. Its totient is φ = 55628881920.

The previous prime is 221607601903. The next prime is 221607601961. The reversal of 221607601920 is 29106706122.

221607601920 is a `hidden beast` number, since 2 + 21 + 6 + 0 + 7 + 601 + 9 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 1359555759 + ... + 1359555921.

It is an arithmetic number, because the mean of its divisors is an integer number (837465344).

Almost surely, 2^221607601920 is an apocalyptic number.

221607601920 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 221607601920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (422082533376).

221607601920 is an abundant number, since it is smaller than the sum of its proper divisors (622557464832).

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

221607601920 is an equidigital number, since it uses as much as digits as its factorization.

221607601920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280 (or 251 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The spelling of 221607601920 in words is "two hundred twenty-one billion, six hundred seven million, six hundred one thousand, nine hundred twenty".