21012133121020 has 24 divisors (see below), whose sum is σ = 44447563352304. Its totient is φ = 8343503953536.

The previous prime is 21012133120919. The next prime is 21012133121029. The reversal of 21012133121020 is 2012133121012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012133121029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3834328122 + ... + 3834333601.

It is an arithmetic number, because the mean of its divisors is an integer number (1851981806346).

Almost surely, 2^{21012133121020} is an apocalyptic number.

21012133121020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012133121020 is an abundant number, since it is smaller than the sum of its proper divisors (23435430231284).

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

21012133121020 is a wasteful number, since it uses less digits than its factorization.

21012133121020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7668661869 (or 7668661867 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 21012133121020 its reverse (2012133121012), we get a palindrome (23024266242032).

The spelling of 21012133121020 in words is "twenty-one trillion, twelve billion, one hundred thirty-three million, one hundred twenty-one thousand, twenty".