165522257 has 4 divisors (see below), whose sum is σ = 165548340. Its totient is φ = 165496176.

The previous prime is 165522241. The next prime is 165522263. The reversal of 165522257 is 752225561.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 752225561 = 19 ⋅39590819.

It can be written as a sum of positive squares in 2 ways, for example, as 101586241 + 63936016 = 10079^2 + 7996^2 .

It is a cyclic number.

It is not a de Polignac number, because 165522257 - 2⁴ = 165522241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165522157) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3323 + ... + 18495.

It is an arithmetic number, because the mean of its divisors is an integer number (41387085).

Almost surely, 2^165522257 is an apocalyptic number.

It is an amenable number.

165522257 is a deficient number, since it is larger than the sum of its proper divisors (26083).

165522257 is a wasteful number, since it uses less digits than its factorization.

165522257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26082.

The product of its digits is 42000, while the sum is 35.

The square root of 165522257 is about 12865.5453440575. The cubic root of 165522257 is about 549.0587283157.

The spelling of 165522257 in words is "one hundred sixty-five million, five hundred twenty-two thousand, two hundred fifty-seven".