20157347857 has 2 divisors, whose sum is σ = 20157347858. Its totient is φ = 20157347856.

The previous prime is 20157347839. The next prime is 20157347891. The reversal of 20157347857 is 75874375102.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14786803201 + 5370544656 = 121601^2 + 73284^2 .

It is a cyclic number.

It is not a de Polignac number, because 20157347857 - 2²⁷ = 20023130129 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20157347857.

It is not a weakly prime, because it can be changed into another prime (20157347807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10078673928 + 10078673929.

It is an arithmetic number, because the mean of its divisors is an integer number (10078673929).

Almost surely, 2^20157347857 is an apocalyptic number.

It is an amenable number.

20157347857 is a deficient number, since it is larger than the sum of its proper divisors (1).

20157347857 is an equidigital number, since it uses as much as digits as its factorization.

20157347857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1646400, while the sum is 49.

The spelling of 20157347857 in words is "twenty billion, one hundred fifty-seven million, three hundred forty-seven thousand, eight hundred fifty-seven".