21068812800 has 600 divisors, whose sum is σ = 89147526336. Its totient is φ = 4814069760.

The previous prime is 21068812799. The next prime is 21068812829. The reversal of 21068812800 is 821886012.

It is a Cunningham number, because it is equal to 145151²-1.

It is a tau number, because it is divible by the number of its divisors (600).

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

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 7256149 + ... + 7259051.

Almost surely, 2^21068812800 is an apocalyptic number.

21068812800 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 21068812800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44573763168).

21068812800 is an abundant number, since it is smaller than the sum of its proper divisors (68078713536).

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

21068812800 is an equidigital number, since it uses as much as digits as its factorization.

21068812800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2950 (or 2920 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The spelling of 21068812800 in words is "twenty-one billion, sixty-eight million, eight hundred twelve thousand, eight hundred".