64665215969 has 2 divisors, whose sum is σ = 64665215970. Its totient is φ = 64665215968.

The previous prime is 64665215947. The next prime is 64665216043. The reversal of 64665215969 is 96951256646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32869690000 + 31795525969 = 181300^2 + 178313^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64665215969 is a prime.

It is a super-2 number, since 2×64665215969² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (64665215929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32332607984 + 32332607985.

It is an arithmetic number, because the mean of its divisors is an integer number (32332607985).

Almost surely, 2^64665215969 is an apocalyptic number.

It is an amenable number.

64665215969 is a deficient number, since it is larger than the sum of its proper divisors (1).

64665215969 is an equidigital number, since it uses as much as digits as its factorization.

64665215969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20995200, while the sum is 59.

The spelling of 64665215969 in words is "sixty-four billion, six hundred sixty-five million, two hundred fifteen thousand, nine hundred sixty-nine".