21144499200 has 924 divisors, whose sum is σ = 86559409248. Its totient is φ = 5076172800.

The previous prime is 21144499199. The next prime is 21144499217. The reversal of 21144499200 is 299444112.

21144499200 is a `hidden beast` number, since 2 + 1 + 1 + 4 + 449 + 9 + 200 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 205286349 + ... + 205286451.

Almost surely, 2^21144499200 is an apocalyptic number.

21144499200 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 21144499200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43279704624).

21144499200 is an abundant number, since it is smaller than the sum of its proper divisors (65414910048).

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

21144499200 is a wasteful number, since it uses less digits than its factorization.

21144499200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The spelling of 21144499200 in words is "twenty-one billion, one hundred forty-four million, four hundred ninety-nine thousand, two hundred".