172675991 has 4 divisors (see below), whose sum is σ = 173630184. Its totient is φ = 171721800.

The previous prime is 172675981. The next prime is 172675999. The reversal of 172675991 is 199576271.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199576271 = 8009 ⋅24919.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-172675991 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 (172675999) 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, 476825 + ... + 477186.

It is an arithmetic number, because the mean of its divisors is an integer number (43407546).

Almost surely, 2^172675991 is an apocalyptic number.

172675991 is a deficient number, since it is larger than the sum of its proper divisors (954193).

172675991 is an equidigital number, since it uses as much as digits as its factorization.

172675991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 954192.

The product of its digits is 238140, while the sum is 47.

The square root of 172675991 is about 13140.6236914387. The cubic root of 172675991 is about 556.8573876871.

The spelling of 172675991 in words is "one hundred seventy-two million, six hundred seventy-five thousand, nine hundred ninety-one".