20975869 has 2 divisors, whose sum is σ = 20975870. Its totient is φ = 20975868.

The previous prime is 20975849. The next prime is 20975879. The reversal of 20975869 is 96857902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20811844 + 164025 = 4562^2 + 405^2 .

It is a cyclic number.

It is not a de Polignac number, because 20975869 - 2⁵ = 20975837 is a prime.

It is a super-2 number, since 2×20975869² = 879974160610322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20975849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10487934 + 10487935.

It is an arithmetic number, because the mean of its divisors is an integer number (10487935).

Almost surely, 2^20975869 is an apocalyptic number.

It is an amenable number.

20975869 is a deficient number, since it is larger than the sum of its proper divisors (1).

20975869 is an equidigital number, since it uses as much as digits as its factorization.

20975869 is an evil number, because the sum of its binary digits is even.

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

The square root of 20975869 is about 4579.9420302008. The cubic root of 20975869 is about 275.7867015807.

The spelling of 20975869 in words is "twenty million, nine hundred seventy-five thousand, eight hundred sixty-nine".