165111220 has 12 divisors (see below), whose sum is σ = 346733604. Its totient is φ = 66044480.

The previous prime is 165111203. The next prime is 165111229. The reversal of 165111220 is 22111561.

It can be written as a sum of positive squares in 2 ways, for example, as 54819216 + 110292004 = 7404^2 + 10502^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165111229) 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, 4127761 + ... + 4127800.

It is an arithmetic number, because the mean of its divisors is an integer number (28894467).

Almost surely, 2^165111220 is an apocalyptic number.

165111220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165111220 is an abundant number, since it is smaller than the sum of its proper divisors (181622384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165111220 is a wasteful number, since it uses less digits than its factorization.

165111220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8255570 (or 8255568 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 19.

The square root of 165111220 is about 12849.5610819981. The cubic root of 165111220 is about 548.6038639650.

Adding to 165111220 its reverse (22111561), we get a palindrome (187222781).

The spelling of 165111220 in words is "one hundred sixty-five million, one hundred eleven thousand, two hundred twenty".