21650556516 has 48 divisors (see below), whose sum is σ = 54366520320. Its totient is φ = 6680977920.

The previous prime is 21650556511. The next prime is 21650556539. The reversal of 21650556516 is 61565505612.

It is not an unprimeable number, because it can be changed into a prime (21650556511) 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, 857476 + ... + 882363.

It is an arithmetic number, because the mean of its divisors is an integer number (1132635840).

Almost surely, 2^21650556516 is an apocalyptic number.

It is an amenable number.

21650556516 is an abundant number, since it is smaller than the sum of its proper divisors (32715963804).

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

21650556516 is a wasteful number, since it uses less digits than its factorization.

21650556516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1739924 (or 1739922 counting only the distinct ones).

The product of its (nonzero) digits is 270000, while the sum is 42.

The spelling of 21650556516 in words is "twenty-one billion, six hundred fifty million, five hundred fifty-six thousand, five hundred sixteen".