2181387264 has 264 divisors, whose sum is σ = 7037880768. Its totient is φ = 588349440.

The previous prime is 2181387253. The next prime is 2181387287. The reversal of 2181387264 is 4627831812.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7762804 + ... + 7763084.

Almost surely, 2^2181387264 is an apocalyptic number.

2181387264 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 2181387264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3518940384).

2181387264 is an abundant number, since it is smaller than the sum of its proper divisors (4856493504).

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

2181387264 is a wasteful number, since it uses less digits than its factorization.

2181387264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349 (or 312 counting only the distinct ones).

The product of its digits is 129024, while the sum is 42.

The square root of 2181387264 is about 46705.3237222482. The cubic root of 2181387264 is about 1296.9132414012.

The spelling of 2181387264 in words is "two billion, one hundred eighty-one million, three hundred eighty-seven thousand, two hundred sixty-four".