81875617 has 4 divisors (see below), whose sum is σ = 86184880. Its totient is φ = 77566356.

The previous prime is 81875611. The next prime is 81875641. The reversal of 81875617 is 71657818.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81875617 - 2³ = 81875609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81875611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2154603 + ... + 2154640.

It is an arithmetic number, because the mean of its divisors is an integer number (21546220).

Almost surely, 2^81875617 is an apocalyptic number.

It is an amenable number.

81875617 is a deficient number, since it is larger than the sum of its proper divisors (4309263).

81875617 is a wasteful number, since it uses less digits than its factorization.

81875617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4309262.

The product of its digits is 94080, while the sum is 43.

The square root of 81875617 is about 9048.5146294848. The cubic root of 81875617 is about 434.2283708944.

The spelling of 81875617 in words is "eighty-one million, eight hundred seventy-five thousand, six hundred seventeen".