21005605605512 has 32 divisors (see below), whose sum is σ = 42970374828000. Its totient is φ = 9547032912000.

The previous prime is 21005605605511. The next prime is 21005605605541. The reversal of 21005605605512 is 21550650650012.

It is not an unprimeable number, because it can be changed into a prime (21005605605511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11248637 + ... + 12982412.

It is an arithmetic number, because the mean of its divisors is an integer number (1342824213375).

Almost surely, 2^{21005605605512} is an apocalyptic number.

21005605605512 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21005605605512 is an abundant number, since it is smaller than the sum of its proper divisors (21964769222488).

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

21005605605512 is a wasteful number, since it uses less digits than its factorization.

21005605605512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24240917 (or 24240913 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 38.

The spelling of 21005605605512 in words is "twenty-one trillion, five billion, six hundred five million, six hundred five thousand, five hundred twelve".