164665 has 4 divisors (see below), whose sum is σ = 197604. Its totient is φ = 131728.

The previous prime is 164663. The next prime is 164677. The reversal of 164665 is 566461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 566461 = 7 ⋅80923.

It can be written as a sum of positive squares in 2 ways, for example, as 29241 + 135424 = 171^2 + 368^2 .

It is a cyclic number.

It is not a de Polignac number, because 164665 - 2¹ = 164663 is a prime.

It is a super-2 number, since 2×164665² = 54229124450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (164663) 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, 16462 + ... + 16471.

It is an arithmetic number, because the mean of its divisors is an integer number (49401).

2¹⁶⁴⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

164665 is a deficient number, since it is larger than the sum of its proper divisors (32939).

164665 is an equidigital number, since it uses as much as digits as its factorization.

164665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32938.

The product of its digits is 4320, while the sum is 28.

The square root of 164665 is about 405.7893542221. The cubic root of 164665 is about 54.8109209769.

It can be divided in two parts, 16466 and 5, that added together give a triangular number (16471 = T₁₈₁).

The spelling of 164665 in words is "one hundred sixty-four thousand, six hundred sixty-five".