20907889 has 4 divisors (see below), whose sum is σ = 21262320. Its totient is φ = 20553460.

The previous prime is 20907877. The next prime is 20907893. The reversal of 20907889 is 98870902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20907889 - 2⁹ = 20907377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20907839) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 177127 + ... + 177244.

It is an arithmetic number, because the mean of its divisors is an integer number (5315580).

Almost surely, 2^20907889 is an apocalyptic number.

It is an amenable number.

20907889 is a deficient number, since it is larger than the sum of its proper divisors (354431).

20907889 is an equidigital number, since it uses as much as digits as its factorization.

20907889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354430.

The product of its (nonzero) digits is 72576, while the sum is 43.

The square root of 20907889 is about 4572.5145161060. The cubic root of 20907889 is about 275.4884498173.

The spelling of 20907889 in words is "twenty million, nine hundred seven thousand, eight hundred eighty-nine".