165521266 has 4 divisors (see below), whose sum is σ = 248281902. Its totient is φ = 82760632.

The previous prime is 165521261. The next prime is 165521303. The reversal of 165521266 is 662125561.

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

It can be written as a sum of positive squares in only one way, i.e., 150921225 + 14600041 = 12285^2 + 3821^2 .

It is not an unprimeable number, because it can be changed into a prime (165521261) 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 as a sum of consecutive naturals, namely, 41380315 + ... + 41380318.

Almost surely, 2^165521266 is an apocalyptic number.

165521266 is a deficient number, since it is larger than the sum of its proper divisors (82760636).

165521266 is an equidigital number, since it uses as much as digits as its factorization.

165521266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82760635.

The product of its digits is 21600, while the sum is 34.

The square root of 165521266 is about 12865.5068302807. The cubic root of 165521266 is about 549.0576325552.

The spelling of 165521266 in words is "one hundred sixty-five million, five hundred twenty-one thousand, two hundred sixty-six".