20993928 has 32 divisors (see below), whose sum is σ = 52620000. Its totient is φ = 6979968.

The previous prime is 20993923. The next prime is 20993939. The reversal of 20993928 is 82939902.

It is a self number, because there is not a number n which added to its sum of digits gives 20993928.

It is not an unprimeable number, because it can be changed into a prime (20993923) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11100 + ... + 12852.

It is an arithmetic number, because the mean of its divisors is an integer number (1644375).

Almost surely, 2^20993928 is an apocalyptic number.

It is an amenable number.

20993928 is an abundant number, since it is smaller than the sum of its proper divisors (31626072).

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

20993928 is a wasteful number, since it uses less digits than its factorization.

20993928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2261 (or 2257 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 42.

The square root of 20993928 is about 4581.9131375442. The cubic root of 20993928 is about 275.8658243009.

The spelling of 20993928 in words is "twenty million, nine hundred ninety-three thousand, nine hundred twenty-eight".