38981313781 has 2 divisors, whose sum is σ = 38981313782. Its totient is φ = 38981313780.

The previous prime is 38981313779. The next prime is 38981313799. The reversal of 38981313781 is 18731318983.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30810780900 + 8170532881 = 175530^2 + 90391^2 .

It is a cyclic number.

It is not a de Polignac number, because 38981313781 - 2¹ = 38981313779 is a prime.

It is a super-2 number, since 2×38981313781² (a number of 22 digits) contains 22 as substring.

Together with 38981313779, 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 (38981323781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19490656890 + 19490656891.

It is an arithmetic number, because the mean of its divisors is an integer number (19490656891).

Almost surely, 2^38981313781 is an apocalyptic number.

It is an amenable number.

38981313781 is a deficient number, since it is larger than the sum of its proper divisors (1).

38981313781 is an equidigital number, since it uses as much as digits as its factorization.

38981313781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 52.

The spelling of 38981313781 in words is "thirty-eight billion, nine hundred eighty-one million, three hundred thirteen thousand, seven hundred eighty-one".