21223143 has 6 divisors (see below), whose sum is σ = 30655664. Its totient is φ = 14148756.

The previous prime is 21223141. The next prime is 21223159. The reversal of 21223143 is 34132212.

It is not a de Polignac number, because 21223143 - 2¹ = 21223141 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223141) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1179055 + ... + 1179072.

Almost surely, 2^21223143 is an apocalyptic number.

21223143 is a deficient number, since it is larger than the sum of its proper divisors (9432521).

21223143 is a wasteful number, since it uses less digits than its factorization.

21223143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2358133 (or 2358130 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 21223143 is about 4606.8582569903. The cubic root of 21223143 is about 276.8661745442.

Adding to 21223143 its reverse (34132212), we get a palindrome (55355355).

The spelling of 21223143 in words is "twenty-one million, two hundred twenty-three thousand, one hundred forty-three".