21366133200 has 180 divisors, whose sum is σ = 75955391148. Its totient is φ = 5558630400.

The previous prime is 21366133067. The next prime is 21366133211. The reversal of 21366133200 is 233166312.

It is a happy number.

21366133200 is a `hidden beast` number, since 2 + 13 + 6 + 613 + 32 + 0 + 0 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 2776446864 + 18589686336 = 52692^2 + 136344^2 .

It is a tau number, because it is divible by the number of its divisors (180).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 75222 + ... + 219978.

Almost surely, 2^21366133200 is an apocalyptic number.

21366133200 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 21366133200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37977695574).

21366133200 is an abundant number, since it is smaller than the sum of its proper divisors (54589257948).

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

21366133200 is a wasteful number, since it uses less digits than its factorization.

21366133200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144822 (or 144808 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

Adding to 21366133200 its reverse (233166312), we get a palindrome (21599299512).

The spelling of 21366133200 in words is "twenty-one billion, three hundred sixty-six million, one hundred thirty-three thousand, two hundred".