21980806524 has 36 divisors (see below), whose sum is σ = 57064289464. Its totient is φ = 7128909792.

The previous prime is 21980806457. The next prime is 21980806531. The reversal of 21980806524 is 42560808912.

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21980806524.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8249722 + ... + 8252385.

Almost surely, 2^21980806524 is an apocalyptic number.

It is an amenable number.

21980806524 is an abundant number, since it is smaller than the sum of its proper divisors (35083482940).

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

21980806524 is a wasteful number, since it uses less digits than its factorization.

21980806524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16502154 (or 16502149 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The spelling of 21980806524 in words is "twenty-one billion, nine hundred eighty million, eight hundred six thousand, five hundred twenty-four".