21919224 has 32 divisors (see below), whose sum is σ = 55336320. Its totient is φ = 7234656.

The previous prime is 21919223. The next prime is 21919237. The reversal of 21919224 is 42291912.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21919191 and 21919200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21919223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1962 + ... + 6905.

It is an arithmetic number, because the mean of its divisors is an integer number (1729260).

Almost surely, 2^21919224 is an apocalyptic number.

21919224 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21919224 is an abundant number, since it is smaller than the sum of its proper divisors (33417096).

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

21919224 is a wasteful number, since it uses less digits than its factorization.

21919224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8979 (or 8975 counting only the distinct ones).

The product of its digits is 2592, while the sum is 30.

The square root of 21919224 is about 4681.7970908616. The cubic root of 21919224 is about 279.8605768457.

The spelling of 21919224 in words is "twenty-one million, nine hundred nineteen thousand, two hundred twenty-four".