20975689 has 4 divisors (see below), whose sum is σ = 23972224. Its totient is φ = 17979156.

The previous prime is 20975687. The next prime is 20975693. The reversal of 20975689 is 98657902.

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 20975689 - 2¹ = 20975687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20975683) 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, 1498257 + ... + 1498270.

It is an arithmetic number, because the mean of its divisors is an integer number (5993056).

Almost surely, 2^20975689 is an apocalyptic number.

It is an amenable number.

20975689 is a deficient number, since it is larger than the sum of its proper divisors (2996535).

20975689 is an equidigital number, since it uses as much as digits as its factorization.

20975689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2996534.

The product of its (nonzero) digits is 272160, while the sum is 46.

The square root of 20975689 is about 4579.9223792549. The cubic root of 20975689 is about 275.7859127100.

The spelling of 20975689 in words is "twenty million, nine hundred seventy-five thousand, six hundred eighty-nine".