20904923 has 8 divisors (see below), whose sum is σ = 23037168. Its totient is φ = 18847584.

The previous prime is 20904899. The next prime is 20904931. The reversal of 20904923 is 32940902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20904923 - 2⁶ = 20904859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20904973) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 18140 + ... + 19257.

It is an arithmetic number, because the mean of its divisors is an integer number (2879646).

Almost surely, 2^20904923 is an apocalyptic number.

20904923 is a deficient number, since it is larger than the sum of its proper divisors (2132245).

20904923 is a wasteful number, since it uses less digits than its factorization.

20904923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37453.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 20904923 is about 4572.1901753973. The cubic root of 20904923 is about 275.4754222406.

The spelling of 20904923 in words is "twenty million, nine hundred four thousand, nine hundred twenty-three".