2165140100 has 144 divisors (see below), whose sum is σ = 5024584656. Its totient is φ = 808704000.

The previous prime is 2165140091. The next prime is 2165140127. The reversal of 2165140100 is 10415612.

It can be written as a sum of positive squares in 24 ways, for example, as 1919841856 + 245298244 = 43816^2 + 15662^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11962010 + ... + 11962190.

It is an arithmetic number, because the mean of its divisors is an integer number (34892949).

Almost surely, 2^2165140100 is an apocalyptic number.

2165140100 is a gapful number since it is divisible by the number (20) 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 2165140100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2512292328).

2165140100 is an abundant number, since it is smaller than the sum of its proper divisors (2859444556).

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

2165140100 is a wasteful number, since it uses less digits than its factorization.

2165140100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346 (or 339 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 2165140100 is about 46531.0659667281. The cubic root of 2165140100 is about 1293.6853730154.

Adding to 2165140100 its reverse (10415612), we get a palindrome (2175555712).

The spelling of 2165140100 in words is "two billion, one hundred sixty-five million, one hundred forty thousand, one hundred".