63381343981 has 2 divisors, whose sum is σ = 63381343982. Its totient is φ = 63381343980.

The previous prime is 63381343979. The next prime is 63381344011. The reversal of 63381343981 is 18934318336.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54286670025 + 9094673956 = 232995^2 + 95366^2 .

It is a cyclic number.

It is not a de Polignac number, because 63381343981 - 2¹ = 63381343979 is a prime.

It is a super-2 number, since 2×63381343981² (a number of 22 digits) contains 22 as substring.

Together with 63381343979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63381343901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31690671990 + 31690671991.

It is an arithmetic number, because the mean of its divisors is an integer number (31690671991).

Almost surely, 2^63381343981 is an apocalyptic number.

It is an amenable number.

63381343981 is a deficient number, since it is larger than the sum of its proper divisors (1).

63381343981 is an equidigital number, since it uses as much as digits as its factorization.

63381343981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1119744, while the sum is 49.

The spelling of 63381343981 in words is "sixty-three billion, three hundred eighty-one million, three hundred forty-three thousand, nine hundred eighty-one".