21022002020 has 24 divisors (see below), whose sum is σ = 44189485368. Its totient is φ = 8400556800.

The previous prime is 21022002011. The next prime is 21022002041. The reversal of 21022002020 is 2020022012.

It can be written as a sum of positive squares in 4 ways, for example, as 785232484 + 20236769536 = 28022^2 + 142256^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21022001992 and 21022002010.

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, 494321 + ... + 535160.

It is an arithmetic number, because the mean of its divisors is an integer number (1841228557).

Almost surely, 2^21022002020 is an apocalyptic number.

21022002020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21022002020 is an abundant number, since it is smaller than the sum of its proper divisors (23167483348).

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

21022002020 is a wasteful number, since it uses less digits than its factorization.

21022002020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1030511 (or 1030509 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 11.

Adding to 21022002020 its reverse (2020022012), we get a palindrome (23042024032).

The spelling of 21022002020 in words is "twenty-one billion, twenty-two million, two thousand, twenty".