72906173 has 4 divisors (see below), whose sum is σ = 76743360. Its totient is φ = 69068988.

The previous prime is 72906167. The next prime is 72906187. The reversal of 72906173 is 37160927.

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, and also an emirpimes, since its reverse is a distinct semiprime: 37160927 = 6079 ⋅6113.

It is a cyclic number.

It is not a de Polignac number, because 72906173 - 2⁶ = 72906109 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72906133) 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, 1918565 + ... + 1918602.

It is an arithmetic number, because the mean of its divisors is an integer number (19185840).

Almost surely, 2^72906173 is an apocalyptic number.

It is an amenable number.

72906173 is a deficient number, since it is larger than the sum of its proper divisors (3837187).

72906173 is a wasteful number, since it uses less digits than its factorization.

72906173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3837186.

The product of its (nonzero) digits is 15876, while the sum is 35.

The square root of 72906173 is about 8538.5111699874. The cubic root of 72906173 is about 417.7547858561.

The spelling of 72906173 in words is "seventy-two million, nine hundred six thousand, one hundred seventy-three".