21122222020 has 24 divisors (see below), whose sum is σ = 44366727384. Its totient is φ = 8446972416.

The previous prime is 21122221973. The next prime is 21122222057. The reversal of 21122222020 is 2022222112.

It can be written as a sum of positive squares in 4 ways, for example, as 5545185156 + 15577036864 = 74466^2 + 124808^2 .

It is a super-2 number, since 2×21122222020² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21122221985 and 21122222003.

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, 27669 + ... + 207388.

It is an arithmetic number, because the mean of its divisors is an integer number (1848613641).

Almost surely, 2^21122222020 is an apocalyptic number.

21122222020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21122222020 is an abundant number, since it is smaller than the sum of its proper divisors (23244505364).

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

21122222020 is a wasteful number, since it uses less digits than its factorization.

21122222020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239559 (or 239557 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21122222020 its reverse (2022222112), we get a palindrome (23144444132).

The spelling of 21122222020 in words is "twenty-one billion, one hundred twenty-two million, two hundred twenty-two thousand, twenty".