2165091264 has 252 divisors, whose sum is σ = 7399068768. Its totient is φ = 603187200.

The previous prime is 2165091241. The next prime is 2165091281. The reversal of 2165091264 is 4621905612.

2165091264 is a `hidden beast` number, since 21 + 6 + 509 + 126 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (252).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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 35 ways as a sum of consecutive naturals, for example, 1156249 + ... + 1158119.

It is an arithmetic number, because the mean of its divisors is an integer number (29361384).

Almost surely, 2^2165091264 is an apocalyptic number.

2165091264 is a gapful number since it is divisible by the number (24) 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 2165091264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3699534384).

2165091264 is an abundant number, since it is smaller than the sum of its proper divisors (5233977504).

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

2165091264 is a wasteful number, since it uses less digits than its factorization.

2165091264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1944 (or 1924 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 2165091264 is about 46530.5411960789. The cubic root of 2165091264 is about 1293.6756463325.

Adding to 2165091264 its reverse (4621905612), we get a palindrome (6786996876).

The spelling of 2165091264 in words is "two billion, one hundred sixty-five million, ninety-one thousand, two hundred sixty-four".