20916889 has 8 divisors (see below), whose sum is σ = 23950080. Its totient is φ = 17894976.

The previous prime is 20916887. The next prime is 20916893. The reversal of 20916889 is 98861902.

It is a happy number.

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 20916889 - 2¹ = 20916887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20916887) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1632 + ... + 6670.

It is an arithmetic number, because the mean of its divisors is an integer number (2993760).

Almost surely, 2^20916889 is an apocalyptic number.

It is an amenable number.

20916889 is a deficient number, since it is larger than the sum of its proper divisors (3033191).

20916889 is an equidigital number, since it uses as much as digits as its factorization.

20916889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5639.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 20916889 is about 4573.4985514374. The cubic root of 20916889 is about 275.5279730227.

The spelling of 20916889 in words is "twenty million, nine hundred sixteen thousand, eight hundred eighty-nine".