21780932992 has 64 divisors (see below), whose sum is σ = 53405200800. Its totient is φ = 8616628224.

The previous prime is 21780932989. The next prime is 21780933017. The reversal of 21780932992 is 29923908712.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (52).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 923317 + ... + 946612.

Almost surely, 2^21780932992 is an apocalyptic number.

It is an amenable number.

21780932992 is an abundant number, since it is smaller than the sum of its proper divisors (31624267808).

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

21780932992 is a wasteful number, since it uses less digits than its factorization.

21780932992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1869963 (or 1869951 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 52.

The spelling of 21780932992 in words is "twenty-one billion, seven hundred eighty million, nine hundred thirty-two thousand, nine hundred ninety-two".