20879717 has 2 divisors, whose sum is σ = 20879718. Its totient is φ = 20879716.

The previous prime is 20879711. The next prime is 20879741. The reversal of 20879717 is 71797802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20016676 + 863041 = 4474^2 + 929^2 .

It is a cyclic number.

It is not a de Polignac number, because 20879717 - 2²² = 16685413 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20879711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10439858 + 10439859.

It is an arithmetic number, because the mean of its divisors is an integer number (10439859).

Almost surely, 2^20879717 is an apocalyptic number.

It is an amenable number.

20879717 is a deficient number, since it is larger than the sum of its proper divisors (1).

20879717 is an equidigital number, since it uses as much as digits as its factorization.

20879717 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 49392, while the sum is 41.

The square root of 20879717 is about 4569.4328969797. The cubic root of 20879717 is about 275.3646600354.

The spelling of 20879717 in words is "twenty million, eight hundred seventy-nine thousand, seven hundred seventeen".