221021200020 has 96 divisors (see below), whose sum is σ = 655404825600. Its totient is φ = 55459969024.

The previous prime is 221021199991. The next prime is 221021200069. The reversal of 221021200020 is 20002120122.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 221021199969 and 221021200005.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 5271901 + ... + 5313659.

It is an arithmetic number, because the mean of its divisors is an integer number (6827133600).

Almost surely, 2^221021200020 is an apocalyptic number.

221021200020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221021200020 is an abundant number, since it is smaller than the sum of its proper divisors (434383625580).

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

221021200020 is a wasteful number, since it uses less digits than its factorization.

221021200020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46977 (or 46975 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 221021200020 its reverse (20002120122), we get a palindrome (241023320142).

The spelling of 221021200020 in words is "two hundred twenty-one billion, twenty-one million, two hundred thousand, twenty".