64956065981 has 2 divisors, whose sum is σ = 64956065982. Its totient is φ = 64956065980.

The previous prime is 64956065939. The next prime is 64956066011. The reversal of 64956065981 is 18956065946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61536740356 + 3419325625 = 248066^2 + 58475^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64956065981 is a prime.

It is a super-2 number, since 2×64956065981² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 64956065981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64956062981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32478032990 + 32478032991.

It is an arithmetic number, because the mean of its divisors is an integer number (32478032991).

Almost surely, 2^64956065981 is an apocalyptic number.

It is an amenable number.

64956065981 is a deficient number, since it is larger than the sum of its proper divisors (1).

64956065981 is an equidigital number, since it uses as much as digits as its factorization.

64956065981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13996800, while the sum is 59.

The spelling of 64956065981 in words is "sixty-four billion, nine hundred fifty-six million, sixty-five thousand, nine hundred eighty-one".