63815758681 has 2 divisors, whose sum is σ = 63815758682. Its totient is φ = 63815758680.

The previous prime is 63815758663. The next prime is 63815758693. The reversal of 63815758681 is 18685751836.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47504382025 + 16311376656 = 217955^2 + 127716^2 .

It is a cyclic number.

It is not a de Polignac number, because 63815758681 - 2⁹ = 63815758169 is a prime.

It is a super-2 number, since 2×63815758681² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (63815758661) 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, 31907879340 + 31907879341.

It is an arithmetic number, because the mean of its divisors is an integer number (31907879341).

Almost surely, 2^63815758681 is an apocalyptic number.

It is an amenable number.

63815758681 is a deficient number, since it is larger than the sum of its proper divisors (1).

63815758681 is an equidigital number, since it uses as much as digits as its factorization.

63815758681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9676800, while the sum is 58.

The spelling of 63815758681 in words is "sixty-three billion, eight hundred fifteen million, seven hundred fifty-eight thousand, six hundred eighty-one".