21223430 has 16 divisors (see below), whose sum is σ = 38282544. Its totient is φ = 8471520.

The previous prime is 21223427. The next prime is 21223453. The reversal of 21223430 is 3432212.

It is a junction number, because it is equal to n+sod(n) for n = 21223399 and 21223408.

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, 3449 + ... + 7371.

It is an arithmetic number, because the mean of its divisors is an integer number (2392659).

Almost surely, 2^21223430 is an apocalyptic number.

21223430 is a deficient number, since it is larger than the sum of its proper divisors (17059114).

21223430 is a wasteful number, since it uses less digits than its factorization.

21223430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4471.

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 21223430 is about 4606.8894060960. The cubic root of 21223430 is about 276.8674225566.

Adding to 21223430 its reverse (3432212), we get a palindrome (24655642).

The spelling of 21223430 in words is "twenty-one million, two hundred twenty-three thousand, four hundred thirty".