221521520000 has 320 divisors, whose sum is σ = 606259684800. Its totient is φ = 79929600000.

The previous prime is 221521519997. The next prime is 221521520053. The reversal of 221521520000 is 25125122.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (320).

It is a super-2 number, since 2×221521520000² (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 congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 122319095 + ... + 122320905.

It is an arithmetic number, because the mean of its divisors is an integer number (1894561515).

Almost surely, 2^221521520000 is an apocalyptic number.

221521520000 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 221521520000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (303129842400).

221521520000 is an abundant number, since it is smaller than the sum of its proper divisors (384738164800).

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

221521520000 is a wasteful number, since it uses less digits than its factorization.

221521520000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1995 (or 1968 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

Adding to 221521520000 its reverse (25125122), we get a palindrome (221546645122).

The spelling of 221521520000 in words is "two hundred twenty-one billion, five hundred twenty-one million, five hundred twenty thousand".