20923191 has 20 divisors (see below), whose sum is σ = 31589712. Its totient is φ = 13799808.

The previous prime is 20923163. The next prime is 20923207. The reversal of 20923191 is 19132902.

It is not a de Polignac number, because 20923191 - 2⁵ = 20923159 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20923121) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6526 + ... + 9188.

Almost surely, 2^20923191 is an apocalyptic number.

20923191 is a deficient number, since it is larger than the sum of its proper divisors (10666521).

20923191 is an equidigital number, since it uses as much as digits as its factorization.

20923191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2772 (or 2763 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 20923191 is about 4574.1874688298. The cubic root of 20923191 is about 275.5556413012. Note that the first 3 decimals are identical.

The spelling of 20923191 in words is "twenty million, nine hundred twenty-three thousand, one hundred ninety-one".