2181555763200 has 2880 divisors, whose sum is σ = 9754433488800. Its totient is φ = 475634073600.

The previous prime is 2181555763187. The next prime is 2181555763207. The reversal of 2181555763200 is 23675551812.

2181555763200 is a `hidden beast` number, since 2 + 1 + 8 + 1 + 5 + 5 + 5 + 7 + 632 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2880).

It is a super-2 number, since 2×2181555763200² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181555763207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 22490265552 + ... + 22490265648.

Almost surely, 2^{2181555763200} is an apocalyptic number.

2181555763200 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 2181555763200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4877216744400).

2181555763200 is an abundant number, since it is smaller than the sum of its proper divisors (7572877725600).

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

2181555763200 is a wasteful number, since it uses less digits than its factorization.

2181555763200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198 (or 164 counting only the distinct ones).

The product of its (nonzero) digits is 504000, while the sum is 45.

The spelling of 2181555763200 in words is "two trillion, one hundred eighty-one billion, five hundred fifty-five million, seven hundred sixty-three thousand, two hundred".