72171223 has 4 divisors (see below), whose sum is σ = 72249840. Its totient is φ = 72092608.

The previous prime is 72171199. The next prime is 72171241. The reversal of 72171223 is 32217127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32217127 = 59 ⋅546053.

It is a cyclic number.

It is not a de Polignac number, because 72171223 - 2⁵ = 72171191 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 (72171283) 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, 37915 + ... + 39772.

It is an arithmetic number, because the mean of its divisors is an integer number (18062460).

Almost surely, 2^72171223 is an apocalyptic number.

72171223 is a deficient number, since it is larger than the sum of its proper divisors (78617).

72171223 is an equidigital number, since it uses as much as digits as its factorization.

72171223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78616.

The product of its digits is 1176, while the sum is 25.

The square root of 72171223 is about 8495.3647949926. The cubic root of 72171223 is about 416.3462796461.

The spelling of 72171223 in words is "seventy-two million, one hundred seventy-one thousand, two hundred twenty-three".