20971619 has 2 divisors, whose sum is σ = 20971620. Its totient is φ = 20971618.

The previous prime is 20971583. The next prime is 20971627. The reversal of 20971619 is 91617902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20971619 - 2²⁴ = 4194403 is a prime.

It is a super-2 number, since 2×20971619² = 879617606962322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20971219) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10485809 + 10485810.

It is an arithmetic number, because the mean of its divisors is an integer number (10485810).

Almost surely, 2^20971619 is an apocalyptic number.

20971619 is a deficient number, since it is larger than the sum of its proper divisors (1).

20971619 is an equidigital number, since it uses as much as digits as its factorization.

20971619 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6804, while the sum is 35.

The square root of 20971619 is about 4579.4780270245. The cubic root of 20971619 is about 275.7680742610.

The spelling of 20971619 in words is "twenty million, nine hundred seventy-one thousand, six hundred nineteen".