21066224400 has 360 divisors, whose sum is σ = 82156366656. Its totient is φ = 4959820800.

The previous prime is 21066224393. The next prime is 21066224447. The reversal of 21066224400 is 442266012.

21066224400 is a `hidden beast` number, since 210 + 6 + 6 + 2 + 2 + 440 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (360).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1066615 + ... + 1086185.

Almost surely, 2^21066224400 is an apocalyptic number.

21066224400 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 21066224400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41078183328).

21066224400 is an abundant number, since it is smaller than the sum of its proper divisors (61090142256).

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

21066224400 is a wasteful number, since it uses less digits than its factorization.

21066224400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19631 (or 19617 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The spelling of 21066224400 in words is "twenty-one billion, sixty-six million, two hundred twenty-four thousand, four hundred".