21216408300 has 144 divisors (see below), whose sum is σ = 68260214400. Its totient is φ = 5653281600.

The previous prime is 21216408299. The next prime is 21216408313. The reversal of 21216408300 is 380461212.

21216408300 is a `hidden beast` number, since 2 + 12 + 1 + 640 + 8 + 3 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4887531 + ... + 4891869.

Almost surely, 2^21216408300 is an apocalyptic number.

21216408300 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 21216408300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34130107200).

21216408300 is an abundant number, since it is smaller than the sum of its proper divisors (47043806100).

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

21216408300 is a wasteful number, since it uses less digits than its factorization.

21216408300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6173 (or 6160 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

Adding to 21216408300 its reverse (380461212), we get a palindrome (21596869512).

The spelling of 21216408300 in words is "twenty-one billion, two hundred sixteen million, four hundred eight thousand, three hundred".