81693113 has 2 divisors, whose sum is σ = 81693114. Its totient is φ = 81693112.

The previous prime is 81693089. The next prime is 81693173. The reversal of 81693113 is 31139618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54361129 + 27331984 = 7373^2 + 5228^2 .

It is a cyclic number.

It is not a de Polignac number, because 81693113 - 2⁶ = 81693049 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81693113.

It is not a weakly prime, because it can be changed into another prime (81693173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40846556 + 40846557.

It is an arithmetic number, because the mean of its divisors is an integer number (40846557).

Almost surely, 2^81693113 is an apocalyptic number.

It is an amenable number.

81693113 is a deficient number, since it is larger than the sum of its proper divisors (1).

81693113 is an equidigital number, since it uses as much as digits as its factorization.

81693113 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 32.

The square root of 81693113 is about 9038.4242542603. The cubic root of 81693113 is about 433.9054934487.

The spelling of 81693113 in words is "eighty-one million, six hundred ninety-three thousand, one hundred thirteen".