165121205 has 8 divisors (see below), whose sum is σ = 201394104. Its totient is φ = 129931200.

The previous prime is 165121193. The next prime is 165121207. The reversal of 165121205 is 502121561.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 21169201 + 143952004 = 4601^2 + 11998^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 165121205 - 2⁴ = 165121189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165121207) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 270386 + ... + 270995.

It is an arithmetic number, because the mean of its divisors is an integer number (25174263).

Almost surely, 2^165121205 is an apocalyptic number.

It is an amenable number.

165121205 is a deficient number, since it is larger than the sum of its proper divisors (36272899).

165121205 is an equidigital number, since it uses as much as digits as its factorization.

165121205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 541447.

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 165121205 is about 12849.9496107961. The cubic root of 165121205 is about 548.6149225697.

Adding to 165121205 its reverse (502121561), we get a palindrome (667242766).

The spelling of 165121205 in words is "one hundred sixty-five million, one hundred twenty-one thousand, two hundred five".