21605102176056 has 64 divisors (see below), whose sum is σ = 61729970158080. Its totient is φ = 6172775656320.

The previous prime is 21605102176003. The next prime is 21605102176057. The reversal of 21605102176056 is 65067120150612.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 21605102175999 and 21605102176017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21605102176057) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8483770 + ... + 10732406.

It is an arithmetic number, because the mean of its divisors is an integer number (964530783720).

Almost surely, 2^{21605102176056} is an apocalyptic number.

It is an amenable number.

21605102176056 is an abundant number, since it is smaller than the sum of its proper divisors (40124867982024).

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

21605102176056 is a wasteful number, since it uses less digits than its factorization.

21605102176056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2305844 (or 2305840 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 42.

The spelling of 21605102176056 in words is "twenty-one trillion, six hundred five billion, one hundred two million, one hundred seventy-six thousand, fifty-six".