21029224 has 16 divisors (see below), whose sum is σ = 39478500. Its totient is φ = 10501632.

The previous prime is 21029207. The next prime is 21029237. The reversal of 21029224 is 42292012.

It can be written as a sum of positive squares in 2 ways, for example, as 20088324 + 940900 = 4482^2 + 970^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21029195 and 21029204.

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, 11544 + ... + 13240.

Almost surely, 2^21029224 is an apocalyptic number.

It is an amenable number.

21029224 is a deficient number, since it is larger than the sum of its proper divisors (18449276).

21029224 is a wasteful number, since it uses less digits than its factorization.

21029224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3252 (or 3248 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 21029224 is about 4585.7631862101. The cubic root of 21029224 is about 276.0203373658.

The spelling of 21029224 in words is "twenty-one million, twenty-nine thousand, two hundred twenty-four".