81793193 has 2 divisors, whose sum is σ = 81793194. Its totient is φ = 81793192.

The previous prime is 81793183. The next prime is 81793241. The reversal of 81793193 is 39139718.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54051904 + 27741289 = 7352^2 + 5267^2 .

It is a cyclic number.

It is not a de Polignac number, because 81793193 - 2²² = 77598889 is a prime.

It is a super-2 number, since 2×81793193² = 13380252842270498, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81793193.

It is not a weakly prime, because it can be changed into another prime (81793183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40896596 + 40896597.

It is an arithmetic number, because the mean of its divisors is an integer number (40896597).

Almost surely, 2^81793193 is an apocalyptic number.

It is an amenable number.

81793193 is a deficient number, since it is larger than the sum of its proper divisors (1).

81793193 is an equidigital number, since it uses as much as digits as its factorization.

81793193 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 41.

The square root of 81793193 is about 9043.9589229496. The cubic root of 81793193 is about 434.0826097286.

The spelling of 81793193 in words is "eighty-one million, seven hundred ninety-three thousand, one hundred ninety-three".