20856725699 has 2 divisors, whose sum is σ = 20856725700. Its totient is φ = 20856725698.

The previous prime is 20856725653. The next prime is 20856725717. The reversal of 20856725699 is 99652765802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20856725699 - 2²⁴ = 20839948483 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (20856725639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10428362849 + 10428362850.

It is an arithmetic number, because the mean of its divisors is an integer number (10428362850).

Almost surely, 2^20856725699 is an apocalyptic number.

20856725699 is a deficient number, since it is larger than the sum of its proper divisors (1).

20856725699 is an equidigital number, since it uses as much as digits as its factorization.

20856725699 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16329600, while the sum is 59.

The spelling of 20856725699 in words is "twenty billion, eight hundred fifty-six million, seven hundred twenty-five thousand, six hundred ninety-nine".