81758173 has 8 divisors (see below), whose sum is σ = 93512448. Its totient is φ = 70022544.

The previous prime is 81758161. The next prime is 81758177. The reversal of 81758173 is 37185718.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81758173 - 2⁹ = 81757661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81758177) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6540 + ... + 14362.

It is an arithmetic number, because the mean of its divisors is an integer number (11689056).

Almost surely, 2^81758173 is an apocalyptic number.

It is an amenable number.

81758173 is a deficient number, since it is larger than the sum of its proper divisors (11754275).

81758173 is a wasteful number, since it uses less digits than its factorization.

81758173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9323.

The product of its digits is 47040, while the sum is 40.

The square root of 81758173 is about 9042.0226166494. The cubic root of 81758173 is about 434.0206496294.

The spelling of 81758173 in words is "eighty-one million, seven hundred fifty-eight thousand, one hundred seventy-three".