63251356981 has 2 divisors, whose sum is σ = 63251356982. Its totient is φ = 63251356980.

The previous prime is 63251356963. The next prime is 63251356997. The reversal of 63251356981 is 18965315236.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52562898756 + 10688458225 = 229266^2 + 103385^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-63251356981 is a prime.

It is a super-2 number, since 2×63251356981² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63251356081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31625678490 + 31625678491.

It is an arithmetic number, because the mean of its divisors is an integer number (31625678491).

Almost surely, 2^63251356981 is an apocalyptic number.

It is an amenable number.

63251356981 is a deficient number, since it is larger than the sum of its proper divisors (1).

63251356981 is an equidigital number, since it uses as much as digits as its factorization.

63251356981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1166400, while the sum is 49.

The spelling of 63251356981 in words is "sixty-three billion, two hundred fifty-one million, three hundred fifty-six thousand, nine hundred eighty-one".