21893280 has 96 divisors (see below), whose sum is σ = 73047744. Its totient is φ = 5492736.

The previous prime is 21893279. The next prime is 21893281. The reversal of 21893280 is 8239812.

It is an interprime number because it is at equal distance from previous prime (21893279) and next prime (21893281).

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (21893281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6819 + ... + 9501.

It is an arithmetic number, because the mean of its divisors is an integer number (760914).

Almost surely, 2^21893280 is an apocalyptic number.

21893280 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 21893280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36523872).

21893280 is an abundant number, since it is smaller than the sum of its proper divisors (51154464).

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

21893280 is a wasteful number, since it uses less digits than its factorization.

21893280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2718 (or 2710 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 21893280 is about 4679.0255395755. The cubic root of 21893280 is about 279.7501171973.

The spelling of 21893280 in words is "twenty-one million, eight hundred ninety-three thousand, two hundred eighty".