63126728681 has 2 divisors, whose sum is σ = 63126728682. Its totient is φ = 63126728680.

The previous prime is 63126728647. The next prime is 63126728701. The reversal of 63126728681 is 18682762136.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62790336400 + 336392281 = 250580^2 + 18341^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-63126728681 is a prime.

It is a super-2 number, since 2×63126728681² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (63126728081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31563364340 + 31563364341.

It is an arithmetic number, because the mean of its divisors is an integer number (31563364341).

Almost surely, 2^63126728681 is an apocalyptic number.

It is an amenable number.

63126728681 is a deficient number, since it is larger than the sum of its proper divisors (1).

63126728681 is an equidigital number, since it uses as much as digits as its factorization.

63126728681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1161216, while the sum is 50.

The spelling of 63126728681 in words is "sixty-three billion, one hundred twenty-six million, seven hundred twenty-eight thousand, six hundred eighty-one".