81377713 has 2 divisors, whose sum is σ = 81377714. Its totient is φ = 81377712.

The previous prime is 81377701. The next prime is 81377729. The reversal of 81377713 is 31777318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71436304 + 9941409 = 8452^2 + 3153^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81377713 is a prime.

It is a super-2 number, since 2×81377713² = 13244664346220738, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81377753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40688856 + 40688857.

It is an arithmetic number, because the mean of its divisors is an integer number (40688857).

Almost surely, 2^81377713 is an apocalyptic number.

It is an amenable number.

81377713 is a deficient number, since it is larger than the sum of its proper divisors (1).

81377713 is an equidigital number, since it uses as much as digits as its factorization.

81377713 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24696, while the sum is 37.

The square root of 81377713 is about 9020.9596496160. The cubic root of 81377713 is about 433.3463671951.

The spelling of 81377713 in words is "eighty-one million, three hundred seventy-seven thousand, seven hundred thirteen".