164172891 has 4 divisors (see below), whose sum is σ = 218897192. Its totient is φ = 109448592.

The previous prime is 164172889. The next prime is 164172913. The reversal of 164172891 is 198271461.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 164172891 - 2¹ = 164172889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (164172821) 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, 27362146 + ... + 27362151.

It is an arithmetic number, because the mean of its divisors is an integer number (54724298).

Almost surely, 2^164172891 is an apocalyptic number.

164172891 is a deficient number, since it is larger than the sum of its proper divisors (54724301).

164172891 is an equidigital number, since it uses as much as digits as its factorization.

164172891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54724300.

The product of its digits is 24192, while the sum is 39.

The square root of 164172891 is about 12812.9969562160. The cubic root of 164172891 is about 547.5626483220.

The spelling of 164172891 in words is "one hundred sixty-four million, one hundred seventy-two thousand, eight hundred ninety-one".