165242121 has 16 divisors (see below), whose sum is σ = 248107008. Its totient is φ = 96915600.

The previous prime is 165242093. The next prime is 165242123. The reversal of 165242121 is 121242561.

It is not a de Polignac number, because 165242121 - 2⁵ = 165242089 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 165242091 and 165242100.

It is not an unprimeable number, because it can be changed into a prime (165242123) by changing a digit.

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, 79741 + ... + 81786.

It is an arithmetic number, because the mean of its divisors is an integer number (15506688).

Almost surely, 2^165242121 is an apocalyptic number.

165242121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

165242121 is a deficient number, since it is larger than the sum of its proper divisors (82864887).

165242121 is a wasteful number, since it uses less digits than its factorization.

165242121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161572.

The product of its digits is 960, while the sum is 24.

The square root of 165242121 is about 12854.6536709473. The cubic root of 165242121 is about 548.7488042965.

Adding to 165242121 its reverse (121242561), we get a palindrome (286484682).

The spelling of 165242121 in words is "one hundred sixty-five million, two hundred forty-two thousand, one hundred twenty-one".