81170645 has 16 divisors (see below), whose sum is σ = 100009728. Its totient is φ = 63215040.

The previous prime is 81170599. The next prime is 81170659. The reversal of 81170645 is 54607118.

It is a happy number.

It is not a de Polignac number, because 81170645 - 2¹² = 81166549 is a prime.

It is a Duffinian number.

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 15 ways as a sum of consecutive naturals, for example, 48767 + ... + 50403.

It is an arithmetic number, because the mean of its divisors is an integer number (6250608).

Almost surely, 2^81170645 is an apocalyptic number.

It is an amenable number.

81170645 is a deficient number, since it is larger than the sum of its proper divisors (18839083).

81170645 is a wasteful number, since it uses less digits than its factorization.

81170645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1900.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 81170645 is about 9009.4752899378. The cubic root of 81170645 is about 432.9785007824.

The spelling of 81170645 in words is "eighty-one million, one hundred seventy thousand, six hundred forty-five".