64757911681 has 2 divisors, whose sum is σ = 64757911682. Its totient is φ = 64757911680.

The previous prime is 64757911651. The next prime is 64757911709. The reversal of 64757911681 is 18611975746.

64757911681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64719360000 + 38551681 = 254400^2 + 6209^2 .

It is a cyclic number.

It is not a de Polignac number, because 64757911681 - 2¹¹ = 64757909633 is a prime.

It is a super-2 number, since 2×64757911681² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (64757911651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32378955840 + 32378955841.

It is an arithmetic number, because the mean of its divisors is an integer number (32378955841).

Almost surely, 2^64757911681 is an apocalyptic number.

It is an amenable number.

64757911681 is a deficient number, since it is larger than the sum of its proper divisors (1).

64757911681 is an equidigital number, since it uses as much as digits as its factorization.

64757911681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2540160, while the sum is 55.

The spelling of 64757911681 in words is "sixty-four billion, seven hundred fifty-seven million, nine hundred eleven thousand, six hundred eighty-one".