165350221 has 4 divisors (see below), whose sum is σ = 165552444. Its totient is φ = 165148000.

The previous prime is 165350219. The next prime is 165350233. The reversal of 165350221 is 122053561.

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

It can be written as a sum of positive squares in 2 ways, for example, as 35640900 + 129709321 = 5970^2 + 11389^2 .

It is a cyclic number.

It is not a de Polignac number, because 165350221 - 2¹ = 165350219 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 (165350261) 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, 99880 + ... + 101521.

It is an arithmetic number, because the mean of its divisors is an integer number (41388111).

Almost surely, 2^165350221 is an apocalyptic number.

It is an amenable number.

165350221 is a deficient number, since it is larger than the sum of its proper divisors (202223).

165350221 is an equidigital number, since it uses as much as digits as its factorization.

165350221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202222.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 165350221 is about 12858.8576864354. The cubic root of 165350221 is about 548.8684404898.

The spelling of 165350221 in words is "one hundred sixty-five million, three hundred fifty thousand, two hundred twenty-one".