20657699 has 2 divisors, whose sum is σ = 20657700. Its totient is φ = 20657698.

The previous prime is 20657677. The next prime is 20657717. The reversal of 20657699 is 99675602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20657699 - 2²⁰ = 19609123 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20657999) 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, 10328849 + 10328850.

It is an arithmetic number, because the mean of its divisors is an integer number (10328850).

Almost surely, 2^20657699 is an apocalyptic number.

20657699 is a deficient number, since it is larger than the sum of its proper divisors (1).

20657699 is an equidigital number, since it uses as much as digits as its factorization.

20657699 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 20657699 is about 4545.0741468099. The cubic root of 20657699 is about 274.3851785252.

The spelling of 20657699 in words is "twenty million, six hundred fifty-seven thousand, six hundred ninety-nine".