21122012020 has 12 divisors (see below), whose sum is σ = 44356225284. Its totient is φ = 8448804800.

The previous prime is 21122011991. The next prime is 21122012053. The reversal of 21122012020 is 2021022112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 4792239076 + 16329772944 = 69226^2 + 127788^2 .

It is a super-2 number, since 2×21122012020² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 528050281 + ... + 528050320.

It is an arithmetic number, because the mean of its divisors is an integer number (3696352107).

Almost surely, 2^21122012020 is an apocalyptic number.

21122012020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21122012020 is an abundant number, since it is smaller than the sum of its proper divisors (23234213264).

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

21122012020 is a wasteful number, since it uses less digits than its factorization.

21122012020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1056100610 (or 1056100608 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21122012020 its reverse (2021022112), we get a palindrome (23143034132).

The spelling of 21122012020 in words is "twenty-one billion, one hundred twenty-two million, twelve thousand, twenty".