643613137 has 2 divisors, whose sum is σ = 643613138. Its totient is φ = 643613136.

The previous prime is 643613077. The next prime is 643613141. The reversal of 643613137 is 731316346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 362178961 + 281434176 = 19031^2 + 16776^2 .

It is a cyclic number.

It is not a de Polignac number, because 643613137 - 2²⁷ = 509395409 is a prime.

It is not a weakly prime, because it can be changed into another prime (643613167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321806568 + 321806569.

It is an arithmetic number, because the mean of its divisors is an integer number (321806569).

Almost surely, 2^643613137 is an apocalyptic number.

It is an amenable number.

643613137 is a deficient number, since it is larger than the sum of its proper divisors (1).

643613137 is an equidigital number, since it uses as much as digits as its factorization.

643613137 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27216, while the sum is 34.

The square root of 643613137 is about 25369.5316669425. The cubic root of 643613137 is about 863.3925561589.

The spelling of 643613137 in words is "six hundred forty-three million, six hundred thirteen thousand, one hundred thirty-seven".