165225138 has 32 divisors (see below), whose sum is σ = 356602176. Its totient is φ = 50733888.

The previous prime is 165225127. The next prime is 165225161. The reversal of 165225138 is 831522561.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 165225099 and 165225108.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 41545 + ... + 45347.

It is an arithmetic number, because the mean of its divisors is an integer number (11143818).

Almost surely, 2^165225138 is an apocalyptic number.

165225138 is an abundant number, since it is smaller than the sum of its proper divisors (191377038).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165225138 is a wasteful number, since it uses less digits than its factorization.

165225138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4378.

The product of its digits is 14400, while the sum is 33.

The square root of 165225138 is about 12853.9930760834. The cubic root of 165225138 is about 548.7300041662.

Adding to 165225138 its reverse (831522561), we get a palindrome (996747699).

The spelling of 165225138 in words is "one hundred sixty-five million, two hundred twenty-five thousand, one hundred thirty-eight".