221721324220 has 48 divisors (see below), whose sum is σ = 534677270400. Its totient is φ = 76382464320.

The previous prime is 221721324203. The next prime is 221721324259. The reversal of 221721324220 is 22423127122.

It is a happy number.

It is a super-2 number, since 2×221721324220² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26517510 + ... + 26525869.

It is an arithmetic number, because the mean of its divisors is an integer number (11139109800).

Almost surely, 2^221721324220 is an apocalyptic number.

221721324220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221721324220 is an abundant number, since it is smaller than the sum of its proper divisors (312955946180).

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

221721324220 is a wasteful number, since it uses less digits than its factorization.

221721324220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53043418 (or 53043416 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 28.

The spelling of 221721324220 in words is "two hundred twenty-one billion, seven hundred twenty-one million, three hundred twenty-four thousand, two hundred twenty".