21246072800 has 144 divisors (see below), whose sum is σ = 53862958800. Its totient is φ = 8173670400.

The previous prime is 21246072769. The next prime is 21246072817. The reversal of 21246072800 is 827064212.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6517571 + ... + 6520829.

It is an arithmetic number, because the mean of its divisors is an integer number (374048325).

Almost surely, 2^21246072800 is an apocalyptic number.

21246072800 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 21246072800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26931479400).

21246072800 is an abundant number, since it is smaller than the sum of its proper divisors (32616886000).

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

21246072800 is a wasteful number, since it uses less digits than its factorization.

21246072800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3589 (or 3576 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 32.

The spelling of 21246072800 in words is "twenty-one billion, two hundred forty-six million, seventy-two thousand, eight hundred".