21450224 has 10 divisors (see below), whose sum is σ = 41559840. Its totient is φ = 10725104.

The previous prime is 21450211. The next prime is 21450229. The reversal of 21450224 is 42205412.

It is a happy number.

It is a super-2 number, since 2×21450224² = 920224219300352, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21450196 and 21450205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21450229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 670304 + ... + 670335.

It is an arithmetic number, because the mean of its divisors is an integer number (4155984).

Almost surely, 2^21450224 is an apocalyptic number.

It is an amenable number.

21450224 is a deficient number, since it is larger than the sum of its proper divisors (20109616).

21450224 is a wasteful number, since it uses less digits than its factorization.

21450224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1340647 (or 1340641 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 21450224 is about 4631.4386533776. The cubic root of 21450224 is about 277.8501340160.

Adding to 21450224 its reverse (42205412), we get a palindrome (63655636).

The spelling of 21450224 in words is "twenty-one million, four hundred fifty thousand, two hundred twenty-four".