20921792 has 14 divisors (see below), whose sum is σ = 41516808. Its totient is φ = 10460864.

The previous prime is 20921777. The next prime is 20921801. The reversal of 20921792 is 29712902.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 163388 + ... + 163515.

Almost surely, 2^20921792 is an apocalyptic number.

It is an amenable number.

20921792 is a deficient number, since it is larger than the sum of its proper divisors (20595016).

20921792 is an equidigital number, since it uses as much as digits as its factorization.

20921792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 326915 (or 326905 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 20921792 is about 4574.0345429391. The cubic root of 20921792 is about 275.5494996164.

The spelling of 20921792 in words is "twenty million, nine hundred twenty-one thousand, seven hundred ninety-two".