64931591509 has 2 divisors, whose sum is σ = 64931591510. Its totient is φ = 64931591508.

The previous prime is 64931591437. The next prime is 64931591521. The reversal of 64931591509 is 90519513946.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61428135409 + 3503456100 = 247847^2 + 59190^2 .

It is a cyclic number.

It is not a de Polignac number, because 64931591509 - 2⁷ = 64931591381 is a prime.

It is a super-2 number, since 2×64931591509² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64931591009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32465795754 + 32465795755.

It is an arithmetic number, because the mean of its divisors is an integer number (32465795755).

Almost surely, 2^64931591509 is an apocalyptic number.

It is an amenable number.

64931591509 is a deficient number, since it is larger than the sum of its proper divisors (1).

64931591509 is an equidigital number, since it uses as much as digits as its factorization.

64931591509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1312200, while the sum is 52.

The spelling of 64931591509 in words is "sixty-four billion, nine hundred thirty-one million, five hundred ninety-one thousand, five hundred nine".