81167687 has 2 divisors, whose sum is σ = 81167688. Its totient is φ = 81167686.

The previous prime is 81167683. The next prime is 81167699. The reversal of 81167687 is 78676118.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81167687 - 2² = 81167683 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81167683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40583843 + 40583844.

It is an arithmetic number, because the mean of its divisors is an integer number (40583844).

Almost surely, 2^81167687 is an apocalyptic number.

81167687 is a deficient number, since it is larger than the sum of its proper divisors (1).

81167687 is an equidigital number, since it uses as much as digits as its factorization.

81167687 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112896, while the sum is 44.

The square root of 81167687 is about 9009.3111279387. The cubic root of 81167687 is about 432.9732412211.

The spelling of 81167687 in words is "eighty-one million, one hundred sixty-seven thousand, six hundred eighty-seven".