21499084800 has 486 divisors, whose sum is σ = 79972227153. Its totient is φ = 5733089280.

The previous prime is 21499084787. The next prime is 21499084811. The reversal of 21499084800 is 848099412.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is a Jordan-Polya number, since it can be written as (6!)² ⋅ (4!)² ⋅ (3!)² ⋅ 2!.

21499084800 is a `hidden beast` number, since 2 + 1 + 499 + 0 + 84 + 80 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 21069103104 + 429981696 = 145152^2 + 20736^2 .

It is a tau number, because it is divible by the number of its divisors (486).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=103680.

It is a super-5 number, since 5×21499084800⁵ (a number of 53 digits) contains 55555 as substring.

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

It is a nialpdrome in base 12.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4299816958 + ... + 4299816962.

Almost surely, 2^21499084800 is an apocalyptic number.

21499084800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21499084800 is a droll number since its even prime factors and its odd prime factors have the same sum.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21499084800

21499084800 is an abundant number, since it is smaller than the sum of its proper divisors (58473142353).

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

21499084800 is an frugal number, since it uses more digits than its factorization.

21499084800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68 (or 10 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

21499084800 divided by its product of nonzero digits (165888) gives a square (129600 = 360²).

The spelling of 21499084800 in words is "twenty-one billion, four hundred ninety-nine million, eighty-four thousand, eight hundred".