21223345 has 16 divisors (see below), whose sum is σ = 29921472. Its totient is φ = 14247360.

The previous prime is 21223333. The next prime is 21223357. The reversal of 21223345 is 54332212.

It is an interprime number because it is at equal distance from previous prime (21223333) and next prime (21223357).

It is not a de Polignac number, because 21223345 - 2²³ = 12834737 is a prime.

It is a Duffinian number.

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, 14127 + ... + 15556.

It is an arithmetic number, because the mean of its divisors is an integer number (1870092).

Almost surely, 2^21223345 is an apocalyptic number.

It is an amenable number.

21223345 is a deficient number, since it is larger than the sum of its proper divisors (8698127).

21223345 is a wasteful number, since it uses less digits than its factorization.

21223345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29712.

The product of its digits is 1440, while the sum is 22.

The square root of 21223345 is about 4606.8801807731. The cubic root of 21223345 is about 276.8670529374.

Adding to 21223345 its reverse (54332212), we get a palindrome (75555557).

The spelling of 21223345 in words is "twenty-one million, two hundred twenty-three thousand, three hundred forty-five".