647765137 has 2 divisors, whose sum is σ = 647765138. Its totient is φ = 647765136.

The previous prime is 647765113. The next prime is 647765143. The reversal of 647765137 is 731567746.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 327211921 + 320553216 = 18089^2 + 17904^2 .

It is a cyclic number.

It is not a de Polignac number, because 647765137 - 2⁷ = 647765009 is a prime.

It is not a weakly prime, because it can be changed into another prime (647765177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323882568 + 323882569.

It is an arithmetic number, because the mean of its divisors is an integer number (323882569).

Almost surely, 2^647765137 is an apocalyptic number.

It is an amenable number.

647765137 is a deficient number, since it is larger than the sum of its proper divisors (1).

647765137 is an equidigital number, since it uses as much as digits as its factorization.

647765137 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 740880, while the sum is 46.

The square root of 647765137 is about 25451.2305596409. The cubic root of 647765137 is about 865.2451829275.

The spelling of 647765137 in words is "six hundred forty-seven million, seven hundred sixty-five thousand, one hundred thirty-seven".