81173901 has 8 divisors (see below), whose sum is σ = 108295200. Its totient is φ = 54084272.

The previous prime is 81173887. The next prime is 81173921. The reversal of 81173901 is 10937118.

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 81173901 - 2⁷ = 81173773 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81173921) 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, 1095 + ... + 12788.

It is an arithmetic number, because the mean of its divisors is an integer number (13536900).

Almost surely, 2^81173901 is an apocalyptic number.

It is an amenable number.

81173901 is a deficient number, since it is larger than the sum of its proper divisors (27121299).

81173901 is a wasteful number, since it uses less digits than its factorization.

81173901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15835.

The product of its (nonzero) digits is 1512, while the sum is 30.

The square root of 81173901 is about 9009.6559867733. The cubic root of 81173901 is about 432.9842900640.

The spelling of 81173901 in words is "eighty-one million, one hundred seventy-three thousand, nine hundred one".