172180823 has 4 divisors (see below), whose sum is σ = 172258080. Its totient is φ = 172103568.

The previous prime is 172180781. The next prime is 172180843. The reversal of 172180823 is 328081271.

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 172180823 - 2¹⁶ = 172115287 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 172180823.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172180843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35183 + ... + 39776.

It is an arithmetic number, because the mean of its divisors is an integer number (43064520).

Almost surely, 2^172180823 is an apocalyptic number.

172180823 is a deficient number, since it is larger than the sum of its proper divisors (77257).

172180823 is an equidigital number, since it uses as much as digits as its factorization.

172180823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77256.

The product of its (nonzero) digits is 5376, while the sum is 32.

The square root of 172180823 is about 13121.7690499414. The cubic root of 172180823 is about 556.3245941625.

The spelling of 172180823 in words is "one hundred seventy-two million, one hundred eighty thousand, eight hundred twenty-three".