21245450 has 12 divisors (see below), whose sum is σ = 39516630. Its totient is φ = 8498160.

The previous prime is 21245417. The next prime is 21245459. The reversal of 21245450 is 5454212.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 17297281 + 3948169 = 4159^2 + 1987^2 .

It is not an unprimeable number, because it can be changed into a prime (21245459) 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, 212405 + ... + 212504.

Almost surely, 2^21245450 is an apocalyptic number.

21245450 is a deficient number, since it is larger than the sum of its proper divisors (18271180).

21245450 is a wasteful number, since it uses less digits than its factorization.

21245450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424921 (or 424916 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 21245450 is about 4609.2786854344. The cubic root of 21245450 is about 276.9631424501.

Adding to 21245450 its reverse (5454212), we get a palindrome (26699662).

The spelling of 21245450 in words is "twenty-one million, two hundred forty-five thousand, four hundred fifty".