21851360 has 48 divisors (see below), whose sum is σ = 52898832. Its totient is φ = 8524800.

The previous prime is 21851351. The next prime is 21851377. The reversal of 21851360 is 6315812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4895 + ... + 8225.

It is an arithmetic number, because the mean of its divisors is an integer number (1102059).

Almost surely, 2^21851360 is an apocalyptic number.

21851360 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 21851360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26449416).

21851360 is an abundant number, since it is smaller than the sum of its proper divisors (31047472).

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

21851360 is a wasteful number, since it uses less digits than its factorization.

21851360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3387 (or 3379 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 21851360 is about 4674.5438280115. The cubic root of 21851360 is about 279.5714532771.

The spelling of 21851360 in words is "twenty-one million, eight hundred fifty-one thousand, three hundred sixty".