647135857 has 2 divisors, whose sum is σ = 647135858. Its totient is φ = 647135856.

The previous prime is 647135807. The next prime is 647135891. The reversal of 647135857 is 758531746.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 438651136 + 208484721 = 20944^2 + 14439^2 .

It is a cyclic number.

It is not a de Polignac number, because 647135857 - 2¹⁹ = 646611569 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (647135807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323567928 + 323567929.

It is an arithmetic number, because the mean of its divisors is an integer number (323567929).

Almost surely, 2^647135857 is an apocalyptic number.

It is an amenable number.

647135857 is a deficient number, since it is larger than the sum of its proper divisors (1).

647135857 is an equidigital number, since it uses as much as digits as its factorization.

647135857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 705600, while the sum is 46.

The square root of 647135857 is about 25438.8650886788. The cubic root of 647135857 is about 864.9649075275.

The spelling of 647135857 in words is "six hundred forty-seven million, one hundred thirty-five thousand, eight hundred fifty-seven".