172623217 has 4 divisors (see below), whose sum is σ = 185901940. Its totient is φ = 159344496.

The previous prime is 172623197. The next prime is 172623233. The reversal of 172623217 is 712326271.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 712326271 = 199 ⋅3579529.

It can be written as a sum of positive squares in 2 ways, for example, as 75620416 + 97002801 = 8696^2 + 9849^2 .

It is a cyclic number.

It is not a de Polignac number, because 172623217 - 2⁷ = 172623089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172623277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6639342 + ... + 6639367.

It is an arithmetic number, because the mean of its divisors is an integer number (46475485).

Almost surely, 2^172623217 is an apocalyptic number.

It is an amenable number.

172623217 is a deficient number, since it is larger than the sum of its proper divisors (13278723).

172623217 is a wasteful number, since it uses less digits than its factorization.

172623217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13278722.

The product of its digits is 7056, while the sum is 31.

The square root of 172623217 is about 13138.6154902257. The cubic root of 172623217 is about 556.8006521677.

Adding to 172623217 its reverse (712326271), we get a palindrome (884949488).

The spelling of 172623217 in words is "one hundred seventy-two million, six hundred twenty-three thousand, two hundred seventeen".