20826713857 has 2 divisors, whose sum is σ = 20826713858. Its totient is φ = 20826713856.

The previous prime is 20826713773. The next prime is 20826713861. The reversal of 20826713857 is 75831762802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20708361216 + 118352641 = 143904^2 + 10879^2 .

It is a cyclic number.

It is not a de Polignac number, because 20826713857 - 2⁷ = 20826713729 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20826713857.

It is not a weakly prime, because it can be changed into another prime (20826713057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10413356928 + 10413356929.

It is an arithmetic number, because the mean of its divisors is an integer number (10413356929).

Almost surely, 2^20826713857 is an apocalyptic number.

It is an amenable number.

20826713857 is a deficient number, since it is larger than the sum of its proper divisors (1).

20826713857 is an equidigital number, since it uses as much as digits as its factorization.

20826713857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1128960, while the sum is 49.

The spelling of 20826713857 in words is "twenty billion, eight hundred twenty-six million, seven hundred thirteen thousand, eight hundred fifty-seven".