72171617 has 4 divisors (see below), whose sum is σ = 82481856. Its totient is φ = 61861380.

The previous prime is 72171611. The next prime is 72171629. The reversal of 72171617 is 71617127.

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, and also an emirpimes, since its reverse is a distinct semiprime: 71617127 = 409 ⋅175103.

It is not a de Polignac number, because 72171617 - 2⁶ = 72171553 is a prime.

It is a super-3 number, since 3×72171617³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72171611) 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, 5155109 + ... + 5155122.

It is an arithmetic number, because the mean of its divisors is an integer number (20620464).

Almost surely, 2^72171617 is an apocalyptic number.

It is an amenable number.

72171617 is a deficient number, since it is larger than the sum of its proper divisors (10310239).

72171617 is a wasteful number, since it uses less digits than its factorization.

72171617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10310238.

The product of its digits is 4116, while the sum is 32.

The square root of 72171617 is about 8495.3879840770. The cubic root of 72171617 is about 416.3470372894.

The spelling of 72171617 in words is "seventy-two million, one hundred seventy-one thousand, six hundred seventeen".