20388923 has 6 divisors (see below), whose sum is σ = 20876004. Its totient is φ = 19912956.

The previous prime is 20388883. The next prime is 20388947. The reversal of 20388923 is 32988302.

It is a de Polignac number, because none of the positive numbers 2^k-20388923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20388323) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3665 + ... + 7362.

It is an arithmetic number, because the mean of its divisors is an integer number (3479334).

Almost surely, 2^20388923 is an apocalyptic number.

20388923 is a deficient number, since it is larger than the sum of its proper divisors (487081).

20388923 is an equidigital number, since it uses as much as digits as its factorization.

20388923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11113 (or 11070 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 20388923 is about 4515.4095052387. The cubic root of 20388923 is about 273.1899772095.

The spelling of 20388923 in words is "twenty million, three hundred eighty-eight thousand, nine hundred twenty-three".