165221300 has 54 divisors (see below), whose sum is σ = 380927442. Its totient is φ = 62190080.

The previous prime is 165221293. The next prime is 165221333. The reversal of 165221300 is 3122561.

165221300 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 9 ways, for example, as 6360484 + 158860816 = 2522^2 + 12604^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 26042 + ... + 31758.

Almost surely, 2^165221300 is an apocalyptic number.

165221300 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 165221300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (190463721).

165221300 is an abundant number, since it is smaller than the sum of its proper divisors (215706142).

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

165221300 is a wasteful number, since it uses less digits than its factorization.

165221300 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5765 (or 5741 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 165221300 is about 12853.8437830868. The cubic root of 165221300 is about 548.7257553332.

Adding to 165221300 its reverse (3122561), we get a palindrome (168343861).

The spelling of 165221300 in words is "one hundred sixty-five million, two hundred twenty-one thousand, three hundred".