64758685681 has 2 divisors, whose sum is σ = 64758685682. Its totient is φ = 64758685680.

The previous prime is 64758685661. The next prime is 64758685751. The reversal of 64758685681 is 18658685746.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64118342656 + 640343025 = 253216^2 + 25305^2 .

It is a cyclic number.

It is not a de Polignac number, because 64758685681 - 2⁷ = 64758685553 is a prime.

It is a super-2 number, since 2×64758685681² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (64758685601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32379342840 + 32379342841.

It is an arithmetic number, because the mean of its divisors is an integer number (32379342841).

Almost surely, 2^64758685681 is an apocalyptic number.

It is an amenable number.

64758685681 is a deficient number, since it is larger than the sum of its proper divisors (1).

64758685681 is an equidigital number, since it uses as much as digits as its factorization.

64758685681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77414400, while the sum is 64.

The spelling of 64758685681 in words is "sixty-four billion, seven hundred fifty-eight million, six hundred eighty-five thousand, six hundred eighty-one".