165165138 has 48 divisors (see below), whose sum is σ = 385912800. Its totient is φ = 50880960.

The previous prime is 165165127. The next prime is 165165163. The reversal of 165165138 is 831561561.

165165138 is a `hidden beast` number, since 1 + 6 + 516 + 5 + 138 = 666.

165165138 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8133 + ... + 19911.

It is an arithmetic number, because the mean of its divisors is an integer number (8039850).

Almost surely, 2^165165138 is an apocalyptic number.

165165138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 165165138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (192956400).

165165138 is an abundant number, since it is smaller than the sum of its proper divisors (220747662).

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

165165138 is a wasteful number, since it uses less digits than its factorization.

165165138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11847 (or 11844 counting only the distinct ones).

The product of its digits is 21600, while the sum is 36.

The square root of 165165138 is about 12851.6589590605. The cubic root of 165165138 is about 548.6635740277.

The spelling of 165165138 in words is "one hundred sixty-five million, one hundred sixty-five thousand, one hundred thirty-eight".