81056845 has 4 divisors (see below), whose sum is σ = 97268220. Its totient is φ = 64845472.

The previous prime is 81056819. The next prime is 81056851. The reversal of 81056845 is 54865018.

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

It can be written as a sum of positive squares in 2 ways, for example, as 17280649 + 63776196 = 4157^2 + 7986^2 .

It is a cyclic number.

It is not a de Polignac number, because 81056845 - 2⁵ = 81056813 is a prime.

It is a congruent number.

It is an unprimeable number.

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, 8105680 + ... + 8105689.

It is an arithmetic number, because the mean of its divisors is an integer number (24317055).

Almost surely, 2^81056845 is an apocalyptic number.

It is an amenable number.

81056845 is a deficient number, since it is larger than the sum of its proper divisors (16211375).

81056845 is a wasteful number, since it uses less digits than its factorization.

81056845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16211374.

The product of its (nonzero) digits is 38400, while the sum is 37.

The square root of 81056845 is about 9003.1575016768. The cubic root of 81056845 is about 432.7760630745.

The spelling of 81056845 in words is "eighty-one million, fifty-six thousand, eight hundred forty-five".