21043250 has 32 divisors (see below), whose sum is σ = 40373424. Its totient is φ = 8208000.

The previous prime is 21043237. The next prime is 21043259. The reversal of 21043250 is 5234012.

It can be written as a sum of positive squares in 8 ways, for example, as 185761 + 20857489 = 431^2 + 4567^2 .

It is not an unprimeable number, because it can be changed into a prime (21043259) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9224 + ... + 11276.

Almost surely, 2^21043250 is an apocalyptic number.

21043250 is a deficient number, since it is larger than the sum of its proper divisors (19330174).

21043250 is a wasteful number, since it uses less digits than its factorization.

21043250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2111 (or 2101 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 21043250 is about 4587.2922296274. The cubic root of 21043250 is about 276.0816900948.

Adding to 21043250 its reverse (5234012), we get a palindrome (26277262).

The spelling of 21043250 in words is "twenty-one million, forty-three thousand, two hundred fifty".