21982806756 has 45 divisors (see below), whose sum is σ = 57474376729. Its totient is φ = 7326712656.

The previous prime is 21982806737. The next prime is 21982806793. The reversal of 21982806756 is 65760828912.

The square root of 21982806756 is 148266.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 13921640100 + 8061166656 = 117990^2 + 89784^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 2664670 + ... + 2672906.

Almost surely, 2^21982806756 is an apocalyptic number.

21982806756 is the 148266-th square number.

It is an amenable number.

21982806756 is an abundant number, since it is smaller than the sum of its proper divisors (35491569973).

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

21982806756 is an frugal number, since it uses more digits than its factorization.

21982806756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16490 (or 8242 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The spelling of 21982806756 in words is "twenty-one billion, nine hundred eighty-two million, eight hundred six thousand, seven hundred fifty-six".