81992845 has 16 divisors (see below), whose sum is σ = 109100160. Its totient is φ = 58651200.

The previous prime is 81992843. The next prime is 81992857. The reversal of 81992845 is 54829918.

It is not a de Polignac number, because 81992845 - 2¹ = 81992843 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81992795 and 81992804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81992843) 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 15 ways as a sum of consecutive naturals, for example, 8865 + ... + 15574.

It is an arithmetic number, because the mean of its divisors is an integer number (6818760).

Almost surely, 2^81992845 is an apocalyptic number.

It is an amenable number.

81992845 is a deficient number, since it is larger than the sum of its proper divisors (27107315).

81992845 is a wasteful number, since it uses less digits than its factorization.

81992845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24516.

The product of its digits is 207360, while the sum is 46.

The square root of 81992845 is about 9054.9900607345. The cubic root of 81992845 is about 434.4355121260.

The spelling of 81992845 in words is "eighty-one million, nine hundred ninety-two thousand, eight hundred forty-five".