2165636564 has 144 divisors (see below), whose sum is σ = 4970020608. Its totient is φ = 803520000.

The previous prime is 2165636527. The next prime is 2165636569. The reversal of 2165636564 is 4656365612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2165636569) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 14341889 + ... + 14342039.

It is an arithmetic number, because the mean of its divisors is an integer number (34514032).

Almost surely, 2^2165636564 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2165636564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2485010304).

2165636564 is an abundant number, since it is smaller than the sum of its proper divisors (2804384044).

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

2165636564 is a wasteful number, since it uses less digits than its factorization.

2165636564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278 (or 245 counting only the distinct ones).

The product of its digits is 777600, while the sum is 44.

The square root of 2165636564 is about 46536.4004194566. The cubic root of 2165636564 is about 1293.7842456212.

The spelling of 2165636564 in words is "two billion, one hundred sixty-five million, six hundred thirty-six thousand, five hundred sixty-four".