21427135200 has 576 divisors, whose sum is σ = 79914885120. Its totient is φ = 5539000320.

The previous prime is 21427135187. The next prime is 21427135207. The reversal of 21427135200 is 253172412.

21427135200 is a `hidden beast` number, since 2 + 1 + 427 + 1 + 35 + 200 = 666.

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 (21427135207) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 168717537 + ... + 168717663.

It is an arithmetic number, because the mean of its divisors is an integer number (138741120).

Almost surely, 2^21427135200 is an apocalyptic number.

21427135200 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 21427135200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39957442560).

21427135200 is an abundant number, since it is smaller than the sum of its proper divisors (58487749920).

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

21427135200 is a wasteful number, since it uses less digits than its factorization.

21427135200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336 (or 317 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The spelling of 21427135200 in words is "twenty-one billion, four hundred twenty-seven million, one hundred thirty-five thousand, two hundred".