221521113020 has 24 divisors (see below), whose sum is σ = 485420179104. Its totient is φ = 84755903936.

The previous prime is 221521112987. The next prime is 221521113061. The reversal of 221521113020 is 20311125122.

It is a super-2 number, since 2×221521113020² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 221521112983 and 221521113001.

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, 240783359 + ... + 240784278.

It is an arithmetic number, because the mean of its divisors is an integer number (20225840796).

Almost surely, 2^221521113020 is an apocalyptic number.

221521113020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221521113020 is an abundant number, since it is smaller than the sum of its proper divisors (263899066084).

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

221521113020 is a wasteful number, since it uses less digits than its factorization.

221521113020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481567669 (or 481567667 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

Adding to 221521113020 its reverse (20311125122), we get a palindrome (241832238142).

The spelling of 221521113020 in words is "two hundred twenty-one billion, five hundred twenty-one million, one hundred thirteen thousand, twenty".