81361079 has 2 divisors, whose sum is σ = 81361080. Its totient is φ = 81361078.

The previous prime is 81361069. The next prime is 81361123. The reversal of 81361079 is 97016318.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81361079 - 2²⁴ = 64583863 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81361069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40680539 + 40680540.

It is an arithmetic number, because the mean of its divisors is an integer number (40680540).

Almost surely, 2^81361079 is an apocalyptic number.

81361079 is a deficient number, since it is larger than the sum of its proper divisors (1).

81361079 is an equidigital number, since it uses as much as digits as its factorization.

81361079 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 81361079 is about 9020.0376385024. The cubic root of 81361079 is about 433.3168391486.

The spelling of 81361079 in words is "eighty-one million, three hundred sixty-one thousand, seventy-nine".