81417173 has 4 divisors (see below), whose sum is σ = 81727008. Its totient is φ = 81107340.

The previous prime is 81417143. The next prime is 81417179. The reversal of 81417173 is 37171418.

It is a happy number.

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 81417173 - 2⁸ = 81416917 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 (81417179) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 154523 + ... + 155048.

It is an arithmetic number, because the mean of its divisors is an integer number (20431752).

Almost surely, 2^81417173 is an apocalyptic number.

It is an amenable number.

81417173 is a deficient number, since it is larger than the sum of its proper divisors (309835).

81417173 is a wasteful number, since it uses less digits than its factorization.

81417173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309834.

The product of its digits is 4704, while the sum is 32.

The square root of 81417173 is about 9023.1465132735. The cubic root of 81417173 is about 433.4163990005.

The spelling of 81417173 in words is "eighty-one million, four hundred seventeen thousand, one hundred seventy-three".