20697659 has 2 divisors, whose sum is σ = 20697660. Its totient is φ = 20697658.

The previous prime is 20697647. The next prime is 20697701. The reversal of 20697659 is 95679602.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20697659 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20697629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10348829 + 10348830.

It is an arithmetic number, because the mean of its divisors is an integer number (10348830).

Almost surely, 2^20697659 is an apocalyptic number.

20697659 is a deficient number, since it is larger than the sum of its proper divisors (1).

20697659 is an equidigital number, since it uses as much as digits as its factorization.

20697659 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 204120, while the sum is 44.

The square root of 20697659 is about 4549.4679908754. The cubic root of 20697659 is about 274.5619870120.

The spelling of 20697659 in words is "twenty million, six hundred ninety-seven thousand, six hundred fifty-nine".