72173851 has 4 divisors (see below), whose sum is σ = 72874672. Its totient is φ = 71473032.

The previous prime is 72173833. The next prime is 72173861. The reversal of 72173851 is 15837127.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 72173851 - 2⁵ = 72173819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72173821) 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, 350256 + ... + 350461.

It is an arithmetic number, because the mean of its divisors is an integer number (18218668).

Almost surely, 2^72173851 is an apocalyptic number.

72173851 is a deficient number, since it is larger than the sum of its proper divisors (700821).

72173851 is a wasteful number, since it uses less digits than its factorization.

72173851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 700820.

The product of its digits is 11760, while the sum is 34.

The square root of 72173851 is about 8495.5194661657. The cubic root of 72173851 is about 416.3513331134.

Subtracting from 72173851 its product of digits (11760), we obtain a triangular number (72162091 = T₁₂₀₁₃).

The spelling of 72173851 in words is "seventy-two million, one hundred seventy-three thousand, eight hundred fifty-one".