21143224 has 16 divisors (see below), whose sum is σ = 39694320. Its totient is φ = 10558080.

The previous prime is 21143207. The next prime is 21143251. The reversal of 21143224 is 42234112.

It is a super-2 number, since 2×21143224² = 894071842228352, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8704 + ... + 10864.

It is an arithmetic number, because the mean of its divisors is an integer number (2480895).

Almost surely, 2^21143224 is an apocalyptic number.

It is an amenable number.

21143224 is a deficient number, since it is larger than the sum of its proper divisors (18551096).

21143224 is a wasteful number, since it uses less digits than its factorization.

21143224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3390 (or 3386 counting only the distinct ones).

The product of its digits is 384, while the sum is 19.

The square root of 21143224 is about 4598.1761601748. The cubic root of 21143224 is about 276.5182100589.

Adding to 21143224 its reverse (42234112), we get a palindrome (63377336).

The spelling of 21143224 in words is "twenty-one million, one hundred forty-three thousand, two hundred twenty-four".