165342581 has 4 divisors (see below), whose sum is σ = 165396000. Its totient is φ = 165289164.

The previous prime is 165342571. The next prime is 165342613. The reversal of 165342581 is 185243561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 185243561 = 29 ⋅6387709.

It is a cyclic number.

It is not a de Polignac number, because 165342581 - 2⁶ = 165342517 is a prime.

It is a super-2 number, since 2×165342581² = 54676338183483122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165342571) 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, 21761 + ... + 28358.

It is an arithmetic number, because the mean of its divisors is an integer number (41349000).

Almost surely, 2^165342581 is an apocalyptic number.

It is an amenable number.

165342581 is a deficient number, since it is larger than the sum of its proper divisors (53419).

165342581 is an equidigital number, since it uses as much as digits as its factorization.

165342581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53418.

The product of its digits is 28800, while the sum is 35.

The square root of 165342581 is about 12858.5606115148. The cubic root of 165342581 is about 548.8599868785.

The spelling of 165342581 in words is "one hundred sixty-five million, three hundred forty-two thousand, five hundred eighty-one".