165526221 has 16 divisors (see below), whose sum is σ = 258097664. Its totient is φ = 92386224.

The previous prime is 165526219. The next prime is 165526243. The reversal of 165526221 is 122625561.

It is not a de Polignac number, because 165526221 - 2¹ = 165526219 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 (165526021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 90751 + ... + 92556.

It is an arithmetic number, because the mean of its divisors is an integer number (16131104).

Almost surely, 2^165526221 is an apocalyptic number.

It is an amenable number.

165526221 is a deficient number, since it is larger than the sum of its proper divisors (92571443).

165526221 is a wasteful number, since it uses less digits than its factorization.

165526221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183360.

The product of its digits is 7200, while the sum is 30.

The square root of 165526221 is about 12865.6993980118. The cubic root of 165526221 is about 549.0631113143.

The spelling of 165526221 in words is "one hundred sixty-five million, five hundred twenty-six thousand, two hundred twenty-one".