165142121 has 6 divisors (see below), whose sum is σ = 167992122. Its totient is φ = 162339680.

The previous prime is 165142111. The next prime is 165142123. The reversal of 165142121 is 121241561.

It can be written as a sum of positive squares in only one way, i.e., 133726096 + 31416025 = 11564^2 + 5605^2 .

It is not a de Polignac number, because 165142121 - 2⁶ = 165142057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165142123) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 20240 + ... + 27201.

It is an arithmetic number, because the mean of its divisors is an integer number (27998687).

Almost surely, 2^165142121 is an apocalyptic number.

It is an amenable number.

165142121 is a deficient number, since it is larger than the sum of its proper divisors (2850001).

165142121 is an frugal number, since it uses more digits than its factorization.

165142121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47559 (or 47500 counting only the distinct ones).

The product of its digits is 480, while the sum is 23.

The square root of 165142121 is about 12850.7634403564. The cubic root of 165142121 is about 548.6380860498.

Adding to 165142121 its reverse (121241561), we get a palindrome (286383682).

The spelling of 165142121 in words is "one hundred sixty-five million, one hundred forty-two thousand, one hundred twenty-one".