221220202020 has 96 divisors (see below), whose sum is σ = 665641888128. Its totient is φ = 54693230592.

The previous prime is 221220202009. The next prime is 221220202031. The reversal of 221220202020 is 20202022122.

It is an interprime number because it is at equal distance from previous prime (221220202009) and next prime (221220202031).

It is a super-2 number, since 2×221220202020² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1550187 + ... + 1686866.

It is an arithmetic number, because the mean of its divisors is an integer number (6933769668).

Almost surely, 2^221220202020 is an apocalyptic number.

221220202020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221220202020 is an abundant number, since it is smaller than the sum of its proper divisors (444421686108).

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

221220202020 is a wasteful number, since it uses less digits than its factorization.

221220202020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3237149 (or 3237147 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

Adding to 221220202020 its reverse (20202022122), we get a palindrome (241422224142).

The spelling of 221220202020 in words is "two hundred twenty-one billion, two hundred twenty million, two hundred two thousand, twenty".