221172713020 has 24 divisors (see below), whose sum is σ = 530814511584. Its totient is φ = 75830644416.

The previous prime is 221172713017. The next prime is 221172713039. The reversal of 221172713020 is 20317271122.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a self number, because there is not a number n which added to its sum of digits gives 221172713020.

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, 789902407 + ... + 789902686.

It is an arithmetic number, because the mean of its divisors is an integer number (22117271316).

Almost surely, 2^221172713020 is an apocalyptic number.

221172713020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221172713020 is an abundant number, since it is smaller than the sum of its proper divisors (309641798564).

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

221172713020 is a wasteful number, since it uses less digits than its factorization.

221172713020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1579805109 (or 1579805107 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 28.

Adding to 221172713020 its reverse (20317271122), we get a palindrome (241489984142).

The spelling of 221172713020 in words is "two hundred twenty-one billion, one hundred seventy-two million, seven hundred thirteen thousand, twenty".