2165271388 has 144 divisors (see below), whose sum is σ = 4826304000. Its totient is φ = 844639488.

The previous prime is 2165271379. The next prime is 2165271391. The reversal of 2165271388 is 8831725612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15577423 + ... + 15577561.

It is an arithmetic number, because the mean of its divisors is an integer number (33516000).

Almost surely, 2^2165271388 is an apocalyptic number.

2165271388 is a gapful number since it is divisible by the number (28) 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 2165271388, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2413152000).

2165271388 is an abundant number, since it is smaller than the sum of its proper divisors (2661032612).

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

2165271388 is a wasteful number, since it uses less digits than its factorization.

2165271388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312 (or 303 counting only the distinct ones).

The product of its digits is 161280, while the sum is 43.

The square root of 2165271388 is about 46532.4767017617. The cubic root of 2165271388 is about 1293.7115209665.

The spelling of 2165271388 in words is "two billion, one hundred sixty-five million, two hundred seventy-one thousand, three hundred eighty-eight".