21102202020 has 24 divisors (see below), whose sum is σ = 59086165824. Its totient is φ = 5627253856.

The previous prime is 21102202007. The next prime is 21102202073. The reversal of 21102202020 is 2020220112.

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 = 21102201987 and 21102202005.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175851624 + ... + 175851743.

It is an arithmetic number, because the mean of its divisors is an integer number (2461923576).

Almost surely, 2^21102202020 is an apocalyptic number.

21102202020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21102202020 is an abundant number, since it is smaller than the sum of its proper divisors (37983963804).

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

21102202020 is a wasteful number, since it uses less digits than its factorization.

21102202020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351703379 (or 351703377 counting only the distinct ones).

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

Adding to 21102202020 its reverse (2020220112), we get a palindrome (23122422132).

The spelling of 21102202020 in words is "twenty-one billion, one hundred two million, two hundred two thousand, twenty".