21024450 has 72 divisors (see below), whose sum is σ = 59482800. Its totient is φ = 5309280.

The previous prime is 21024433. The next prime is 21024457. The reversal of 21024450 is 5442012.

21024450 is a `hidden beast` number, since 210 + 2 + 4 + 450 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21024457) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 7321 + ... + 9779.

It is an arithmetic number, because the mean of its divisors is an integer number (826150).

Almost surely, 2^21024450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21024450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29741400).

21024450 is an abundant number, since it is smaller than the sum of its proper divisors (38458350).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21024450 is a wasteful number, since it uses less digits than its factorization.

21024450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2496 (or 2488 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 21024450 is about 4585.2426326204. The cubic root of 21024450 is about 275.9994486441. Note that the first 3 decimals are identical.

Adding to 21024450 its reverse (5442012), we get a palindrome (26466462).

The spelling of 21024450 in words is "twenty-one million, twenty-four thousand, four hundred fifty".