165025609 has 4 divisors (see below), whose sum is σ = 188600704. Its totient is φ = 141450516.

The previous prime is 165025589. The next prime is 165025633. The reversal of 165025609 is 906520561.

It is a happy number.

165025609 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 906520561 = 16187 ⋅56003.

It is a cyclic number.

It is not a de Polignac number, because 165025609 - 2⁵ = 165025577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165025639) 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, 11787537 + ... + 11787550.

It is an arithmetic number, because the mean of its divisors is an integer number (47150176).

Almost surely, 2^165025609 is an apocalyptic number.

It is an amenable number.

165025609 is a deficient number, since it is larger than the sum of its proper divisors (23575095).

165025609 is an equidigital number, since it uses as much as digits as its factorization.

165025609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23575094.

The product of its (nonzero) digits is 16200, while the sum is 34.

The square root of 165025609 is about 12846.2293689627. The cubic root of 165025609 is about 548.5090296160.

The spelling of 165025609 in words is "one hundred sixty-five million, twenty-five thousand, six hundred nine".