221001021220 has 48 divisors (see below), whose sum is σ = 530659503360. Its totient is φ = 75735057024.

The previous prime is 221001021211. The next prime is 221001021233. The reversal of 221001021220 is 22120100122.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 221001021220.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91824 + ... + 671143.

It is an arithmetic number, because the mean of its divisors is an integer number (11055406320).

Almost surely, 2^221001021220 is an apocalyptic number.

221001021220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221001021220 is an abundant number, since it is smaller than the sum of its proper divisors (309658482140).

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

221001021220 is a wasteful number, since it uses less digits than its factorization.

221001021220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765052 (or 765050 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 221001021220 its reverse (22120100122), we get a palindrome (243121121342).

The spelling of 221001021220 in words is "two hundred twenty-one billion, one million, twenty-one thousand, two hundred twenty".