21113645587200 has 756 divisors, whose sum is σ = 78649466268240. Its totient is φ = 5609041551360.

The previous prime is 21113645587187. The next prime is 21113645587207. The reversal of 21113645587200 is 278554631112.

21113645587200 is a `hidden beast` number, since 2 + 1 + 1 + 1 + 3 + 6 + 45 + 587 + 20 + 0 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (21113645587207) by changing a digit.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 1255037989 + ... + 1255054811.

It is an arithmetic number, because the mean of its divisors is an integer number (104033685540).

Almost surely, 2^{21113645587200} is an apocalyptic number.

21113645587200 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 21113645587200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39324733134120).

21113645587200 is an abundant number, since it is smaller than the sum of its proper divisors (57535820681040).

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

21113645587200 is an equidigital number, since it uses as much as digits as its factorization.

21113645587200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17136 (or 17102 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The spelling of 21113645587200 in words is "twenty-one trillion, one hundred thirteen billion, six hundred forty-five million, five hundred eighty-seven thousand, two hundred".