21005112531100 has 18 divisors (see below), whose sum is σ = 45581094192704. Its totient is φ = 8402045012400.

The previous prime is 21005112531097. The next prime is 21005112531103. The reversal of 21005112531100 is 113521150012.

21005112531100 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (21005112531097) and next prime (21005112531103).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21005112531103) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 105025562556 + ... + 105025562755.

Almost surely, 2^{21005112531100} is an apocalyptic number.

21005112531100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21005112531100 is an abundant number, since it is smaller than the sum of its proper divisors (24575981661604).

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

21005112531100 is a wasteful number, since it uses less digits than its factorization.

21005112531100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210051125325 (or 210051125318 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 22.

Adding to 21005112531100 its reverse (113521150012), we get a palindrome (21118633681112).

The spelling of 21005112531100 in words is "twenty-one trillion, five billion, one hundred twelve million, five hundred thirty-one thousand, one hundred".