221021020020 has 48 divisors (see below), whose sum is σ = 624536478720. Its totient is φ = 58398212736.

The previous prime is 221021020009. The next prime is 221021020021. The reversal of 221021020020 is 20020120122.

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 = 221021019978 and 221021020005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221021020021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16891092 + ... + 16904171.

It is an arithmetic number, because the mean of its divisors is an integer number (13011176640).

Almost surely, 2^221021020020 is an apocalyptic number.

221021020020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221021020020 is an abundant number, since it is smaller than the sum of its proper divisors (403515458700).

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

221021020020 is a wasteful number, since it uses less digits than its factorization.

221021020020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33795384 (or 33795382 counting only the distinct ones).

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

Adding to 221021020020 its reverse (20020120122), we get a palindrome (241041140142).

The spelling of 221021020020 in words is "two hundred twenty-one billion, twenty-one million, twenty thousand, twenty".