81792719 has 4 divisors (see below), whose sum is σ = 81999144. Its totient is φ = 81586296.

The previous prime is 81792709. The next prime is 81792757. The reversal of 81792719 is 91729718.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81792719 - 2⁸ = 81792463 is a prime.

It is a super-2 number, since 2×81792719² = 13380097762825922, which contains 22 as substring.

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 81792719.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81792709) 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 in 3 ways as a sum of consecutive naturals, for example, 102617 + ... + 103410.

It is an arithmetic number, because the mean of its divisors is an integer number (20499786).

Almost surely, 2^81792719 is an apocalyptic number.

81792719 is a deficient number, since it is larger than the sum of its proper divisors (206425).

81792719 is a wasteful number, since it uses less digits than its factorization.

81792719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206424.

The product of its digits is 63504, while the sum is 44.

The square root of 81792719 is about 9043.9327175737. The cubic root of 81792719 is about 434.0817712091.

The spelling of 81792719 in words is "eighty-one million, seven hundred ninety-two thousand, seven hundred nineteen".