2218634640 has 240 divisors, whose sum is σ = 8083451376. Its totient is φ = 543129600.

The previous prime is 2218634591. The next prime is 2218634699. The reversal of 2218634640 is 464368122.

2218634640 is a `hidden beast` number, since 2 + 2 + 1 + 8 + 6 + 3 + 4 + 640 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 1354896 + 2217279744 = 1164^2 + 47088^2 .

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a junction number, because it is equal to n+sod(n) for n = 2218634595 and 2218634604.

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, 499630 + ... + 504050.

Almost surely, 2^2218634640 is an apocalyptic number.

2218634640 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 2218634640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4041725688).

2218634640 is an abundant number, since it is smaller than the sum of its proper divisors (5864816736).

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

2218634640 is a wasteful number, since it uses less digits than its factorization.

2218634640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4498 (or 4489 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 2218634640 is about 47102.3846530088. The cubic root of 2218634640 is about 1304.2532566682.

The spelling of 2218634640 in words is "two billion, two hundred eighteen million, six hundred thirty-four thousand, six hundred forty".