21298636800 has 1152 divisors, whose sum is σ = 93594009600. Its totient is φ = 4644864000.

The previous prime is 21298636787. The next prime is 21298636859. The reversal of 21298636800 is 863689212.

21298636800 is a `hidden beast` number, since 2 + 1 + 2 + 9 + 8 + 636 + 8 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

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

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 95 ways as a sum of consecutive naturals, for example, 299980765 + ... + 299980835.

It is an arithmetic number, because the mean of its divisors is an integer number (81244800).

Almost surely, 2^21298636800 is an apocalyptic number.

21298636800 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 21298636800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46797004800).

21298636800 is an abundant number, since it is smaller than the sum of its proper divisors (72295372800).

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

21298636800 is a wasteful number, since it uses less digits than its factorization.

21298636800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The spelling of 21298636800 in words is "twenty-one billion, two hundred ninety-eight million, six hundred thirty-six thousand, eight hundred".