21440450 has 12 divisors (see below), whose sum is σ = 39879330. Its totient is φ = 8576160.

The previous prime is 21440449. The next prime is 21440453. The reversal of 21440450 is 5404412.

It can be written as a sum of positive squares in 3 ways, for example, as 12033961 + 9406489 = 3469^2 + 3067^2 .

It is a plaindrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (21440453) 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, 214355 + ... + 214454.

Almost surely, 2^21440450 is an apocalyptic number.

21440450 is a deficient number, since it is larger than the sum of its proper divisors (18438880).

21440450 is a wasteful number, since it uses less digits than its factorization.

21440450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428821 (or 428816 counting only the distinct ones).

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

The square root of 21440450 is about 4630.3833534601. The cubic root of 21440450 is about 277.8079259130.

Adding to 21440450 its reverse (5404412), we get a palindrome (26844862).

The spelling of 21440450 in words is "twenty-one million, four hundred forty thousand, four hundred fifty".