21822320 has 40 divisors (see below), whose sum is σ = 54642336. Its totient is φ = 8057088.

The previous prime is 21822293. The next prime is 21822343. The reversal of 21822320 is 2322812.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21822292 and 21822301.

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, 9452 + ... + 11531.

Almost surely, 2^21822320 is an apocalyptic number.

21822320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21822320 is an abundant number, since it is smaller than the sum of its proper divisors (32820016).

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

21822320 is a wasteful number, since it uses less digits than its factorization.

21822320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21009 (or 21003 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 21822320 is about 4671.4366098664. The cubic root of 21822320 is about 279.4475501697.

The spelling of 21822320 in words is "twenty-one million, eight hundred twenty-two thousand, three hundred twenty".