864197857 has 2 divisors, whose sum is σ = 864197858. Its totient is φ = 864197856.

The previous prime is 864197849. The next prime is 864197899. The reversal of 864197857 is 758791468.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 621804096 + 242393761 = 24936^2 + 15569^2 .

It is a cyclic number.

It is not a de Polignac number, because 864197857 - 2³ = 864197849 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 864197798 and 864197807.

It is not a weakly prime, because it can be changed into another prime (864197357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432098928 + 432098929.

It is an arithmetic number, because the mean of its divisors is an integer number (432098929).

Almost surely, 2^864197857 is an apocalyptic number.

It is an amenable number.

864197857 is a deficient number, since it is larger than the sum of its proper divisors (1).

864197857 is an equidigital number, since it uses as much as digits as its factorization.

864197857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3386880, while the sum is 55.

The square root of 864197857 is about 29397.2423366546. The cubic root of 864197857 is about 952.5133289675.

The spelling of 864197857 in words is "eight hundred sixty-four million, one hundred ninety-seven thousand, eight hundred fifty-seven".