81992767 has 4 divisors (see below), whose sum is σ = 82088640. Its totient is φ = 81896896.

The previous prime is 81992759. The next prime is 81992783. The reversal of 81992767 is 76729918.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 76729918 = 2 ⋅38364959.

It is a cyclic number.

It is not a de Polignac number, because 81992767 - 2³ = 81992759 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81992767.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81992707) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46642 + ... + 48367.

It is an arithmetic number, because the mean of its divisors is an integer number (20522160).

Almost surely, 2^81992767 is an apocalyptic number.

81992767 is a deficient number, since it is larger than the sum of its proper divisors (95873).

81992767 is an equidigital number, since it uses as much as digits as its factorization.

81992767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95872.

The product of its digits is 381024, while the sum is 49.

The square root of 81992767 is about 9054.9857537160. The cubic root of 81992767 is about 434.4353743661.

The spelling of 81992767 in words is "eighty-one million, nine hundred ninety-two thousand, seven hundred sixty-seven".