21427944000 has 448 divisors, whose sum is σ = 74130481152. Its totient is φ = 5447424000.

The previous prime is 21427943993. The next prime is 21427944001. The reversal of 21427944000 is 44972412.

It is not an unprimeable number, because it can be changed into a prime (21427944001) 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, 61751827 + ... + 61752173.

It is an arithmetic number, because the mean of its divisors is an integer number (165469824).

Almost surely, 2^21427944000 is an apocalyptic number.

21427944000 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 21427944000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37065240576).

21427944000 is an abundant number, since it is smaller than the sum of its proper divisors (52702537152).

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

21427944000 is a wasteful number, since it uses less digits than its factorization.

21427944000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491 (or 471 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 33.

The spelling of 21427944000 in words is "twenty-one billion, four hundred twenty-seven million, nine hundred forty-four thousand".