2180636640 has 720 divisors, whose sum is σ = 9697187808. Its totient is φ = 449390592.

The previous prime is 2180636629. The next prime is 2180636671. The reversal of 2180636640 is 466360812.

2180636640 is a `hidden beast` number, since 2 + 1 + 8 + 0 + 6 + 3 + 6 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

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 = 2180636595 and 2180636604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 50712459 + ... + 50712501.

Almost surely, 2^2180636640 is an apocalyptic number.

2180636640 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 2180636640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4848593904).

2180636640 is an abundant number, since it is smaller than the sum of its proper divisors (7516551168).

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

2180636640 is a wasteful number, since it uses less digits than its factorization.

2180636640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133 (or 73 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 2180636640 is about 46697.2872873789. The cubic root of 2180636640 is about 1296.7644666737.

The spelling of 2180636640 in words is "two billion, one hundred eighty million, six hundred thirty-six thousand, six hundred forty".