21280536000 has 448 divisors, whose sum is σ = 79083164160. Its totient is φ = 5601715200.

The previous prime is 21280535957. The next prime is 21280536007. The reversal of 21280536000 is 63508212.

21280536000 is a `hidden beast` number, since 2 + 1 + 2 + 8 + 0 + 53 + 600 + 0 = 666.

It is a super-2 number, since 2×21280536000² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21280536007) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 17927407 + ... + 17928593.

It is an arithmetic number, because the mean of its divisors is an integer number (176524920).

Almost surely, 2^21280536000 is an apocalyptic number.

21280536000 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 21280536000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39541582080).

21280536000 is an abundant number, since it is smaller than the sum of its proper divisors (57802628160).

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

21280536000 is a wasteful number, since it uses less digits than its factorization.

21280536000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1306 (or 1280 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The spelling of 21280536000 in words is "twenty-one billion, two hundred eighty million, five hundred thirty-six thousand".