81795645 has 24 divisors (see below), whose sum is σ = 142081056. Its totient is φ = 43531488.

The previous prime is 81795617. The next prime is 81795667. The reversal of 81795645 is 54659718.

81795645 is a `hidden beast` number, since 81 + 7 + 9 + 564 + 5 = 666.

It is not a de Polignac number, because 81795645 - 2¹⁰ = 81794621 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 81795645.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22954 + ... + 26276.

It is an arithmetic number, because the mean of its divisors is an integer number (5920044).

Almost surely, 2^81795645 is an apocalyptic number.

It is an amenable number.

81795645 is a deficient number, since it is larger than the sum of its proper divisors (60285411).

81795645 is a wasteful number, since it uses less digits than its factorization.

81795645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3881 (or 3878 counting only the distinct ones).

The product of its digits is 302400, while the sum is 45.

The square root of 81795645 is about 9044.0944820363. The cubic root of 81795645 is about 434.0869473345.

It can be divided in two parts, 8179 and 5645, that added together give a cube (13824 = 24³).

The spelling of 81795645 in words is "eighty-one million, seven hundred ninety-five thousand, six hundred forty-five".