165215123 has 4 divisors (see below), whose sum is σ = 165631680. Its totient is φ = 164798568.

The previous prime is 165215119. The next prime is 165215161. The reversal of 165215123 is 321512561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165215123 - 2² = 165215119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165215092 and 165215101.

It is not an unprimeable number, because it can be changed into a prime (165215723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 207683 + ... + 208476.

It is an arithmetic number, because the mean of its divisors is an integer number (41407920).

Almost surely, 2^165215123 is an apocalyptic number.

165215123 is a deficient number, since it is larger than the sum of its proper divisors (416557).

165215123 is an equidigital number, since it uses as much as digits as its factorization.

165215123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 416556.

The product of its digits is 1800, while the sum is 26.

The square root of 165215123 is about 12853.6035025202. The cubic root of 165215123 is about 548.7189169872.

Adding to 165215123 its reverse (321512561), we get a palindrome (486727684).

The spelling of 165215123 in words is "one hundred sixty-five million, two hundred fifteen thousand, one hundred twenty-three".