20660879 has 2 divisors, whose sum is σ = 20660880. Its totient is φ = 20660878.

The previous prime is 20660869. The next prime is 20660881. The reversal of 20660879 is 97806602.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20660879 is a prime.

It is a Sophie Germain prime.

Together with 20660881, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20660839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10330439 + 10330440.

It is an arithmetic number, because the mean of its divisors is an integer number (10330440).

Almost surely, 2^20660879 is an apocalyptic number.

20660879 is a deficient number, since it is larger than the sum of its proper divisors (1).

20660879 is an equidigital number, since it uses as much as digits as its factorization.

20660879 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 20660879 is about 4545.4239626244. The cubic root of 20660879 is about 274.3992572165.

The spelling of 20660879 in words is "twenty million, six hundred sixty thousand, eight hundred seventy-nine".