164491 has 4 divisors (see below), whose sum is σ = 166192. Its totient is φ = 162792.

The previous prime is 164477. The next prime is 164503. The reversal of 164491 is 194461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 194461 = 139 ⋅1399.

It is a cyclic number.

It is not a de Polignac number, because 164491 - 2⁷ = 164363 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (164431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 696 + ... + 901.

It is an arithmetic number, because the mean of its divisors is an integer number (41548).

2¹⁶⁴⁴⁹¹ is an apocalyptic number.

164491 is a deficient number, since it is larger than the sum of its proper divisors (1701).

164491 is a wasteful number, since it uses less digits than its factorization.

164491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1700.

The product of its digits is 864, while the sum is 25.

The square root of 164491 is about 405.5749006041. The cubic root of 164491 is about 54.7916081063.

The spelling of 164491 in words is "one hundred sixty-four thousand, four hundred ninety-one".