21032224 has 12 divisors (see below), whose sum is σ = 41407254. Its totient is φ = 10516096.

The previous prime is 21032201. The next prime is 21032237. The reversal of 21032224 is 42223012.

It can be written as a sum of positive squares in only one way, i.e., 19891600 + 1140624 = 4460^2 + 1068^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 21032198 and 21032207.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328597 + ... + 328660.

Almost surely, 2^21032224 is an apocalyptic number.

It is an amenable number.

21032224 is a deficient number, since it is larger than the sum of its proper divisors (20375030).

21032224 is an equidigital number, since it uses as much as digits as its factorization.

21032224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 657267 (or 657259 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21032224 is about 4586.0902738607. The cubic root of 21032224 is about 276.0334623015.

Adding to 21032224 its reverse (42223012), we get a palindrome (63255236).

The spelling of 21032224 in words is "twenty-one million, thirty-two thousand, two hundred twenty-four".