21223158 has 96 divisors (see below), whose sum is σ = 51480576. Its totient is φ = 5808000.

The previous prime is 21223141. The next prime is 21223159. The reversal of 21223158 is 85132212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223159) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 517618 + ... + 517658.

It is an arithmetic number, because the mean of its divisors is an integer number (536256).

Almost surely, 2^21223158 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21223158, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25740288).

21223158 is an abundant number, since it is smaller than the sum of its proper divisors (30257418).

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

21223158 is a wasteful number, since it uses less digits than its factorization.

21223158 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122 (or 111 counting only the distinct ones).

The product of its digits is 960, while the sum is 24.

The square root of 21223158 is about 4606.8598849976. The cubic root of 21223158 is about 276.8662397716.

The spelling of 21223158 in words is "twenty-one million, two hundred twenty-three thousand, one hundred fifty-eight".