21115816806612 has 48 divisors (see below), whose sum is σ = 53792386200000. Its totient is φ = 6393609231360.

The previous prime is 21115816806559. The next prime is 21115816806649. The reversal of 21115816806612 is 21660861851112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 63873687 + ... + 64203422.

It is an arithmetic number, because the mean of its divisors is an integer number (1120674712500).

Almost surely, 2^{21115816806612} is an apocalyptic number.

21115816806612 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21115816806612 is an abundant number, since it is smaller than the sum of its proper divisors (32676569393388).

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

21115816806612 is a wasteful number, since it uses less digits than its factorization.

21115816806612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128078376 (or 128078374 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 48.

The spelling of 21115816806612 in words is "twenty-one trillion, one hundred fifteen billion, eight hundred sixteen million, eight hundred six thousand, six hundred twelve".