21022308 has 48 divisors (see below), whose sum is σ = 55413120. Its totient is φ = 6890400.

The previous prime is 21022279. The next prime is 21022357. The reversal of 21022308 is 80322012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4993 + ... + 8183.

It is an arithmetic number, because the mean of its divisors is an integer number (1154440).

Almost surely, 2^21022308 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21022308, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27706560).

21022308 is an abundant number, since it is smaller than the sum of its proper divisors (34390812).

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

21022308 is a wasteful number, since it uses less digits than its factorization.

21022308 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3265 (or 3257 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21022308 is about 4585.0090512452. The cubic root of 21022308 is about 275.9900752575.

The spelling of 21022308 in words is "twenty-one million, twenty-two thousand, three hundred eight".