165389121 has 20 divisors (see below), whose sum is σ = 253093764. Its totient is φ = 107568000.

The previous prime is 165389111. The next prime is 165389131. The reversal of 165389121 is 121983561.

165389121 is a `hidden beast` number, since 16 + 538 + 91 + 21 = 666.

165389121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (165389111) and next prime (165389131).

It can be written as a sum of positive squares in 2 ways, for example, as 29550096 + 135839025 = 5436^2 + 11655^2 .

It is not a de Polignac number, because 165389121 - 2¹⁵ = 165356353 is a prime.

It is a super-2 number, since 2×165389121² = 54707122690305282, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (165389101) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 21580 + ... + 28221.

Almost surely, 2^165389121 is an apocalyptic number.

It is an amenable number.

165389121 is a deficient number, since it is larger than the sum of its proper divisors (87704643).

165389121 is an equidigital number, since it uses as much as digits as its factorization.

165389121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49854 (or 49845 counting only the distinct ones).

The product of its digits is 12960, while the sum is 36.

The square root of 165389121 is about 12860.3701735214. The cubic root of 165389121 is about 548.9114790538.

The spelling of 165389121 in words is "one hundred sixty-five million, three hundred eighty-nine thousand, one hundred twenty-one".