20924978 has 16 divisors (see below), whose sum is σ = 32166720. Its totient is φ = 10206000.

The previous prime is 20924957. The next prime is 20924987. The reversal of 20924978 is 87942902.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13613 + ... + 15071.

It is an arithmetic number, because the mean of its divisors is an integer number (2010420).

Almost surely, 2^20924978 is an apocalyptic number.

20924978 is a deficient number, since it is larger than the sum of its proper divisors (11241742).

20924978 is a wasteful number, since it uses less digits than its factorization.

20924978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1633.

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 20924978 is about 4574.3827998977. The cubic root of 20924978 is about 275.5634859286.

The spelling of 20924978 in words is "twenty million, nine hundred twenty-four thousand, nine hundred seventy-eight".