21252450 has 48 divisors (see below), whose sum is σ = 55487520. Its totient is φ = 5368320.

The previous prime is 21252443. The next prime is 21252457. The reversal of 21252450 is 5425212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21252443) and next prime (21252457).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21252457) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 879 + ... + 6578.

It is an arithmetic number, because the mean of its divisors is an integer number (1155990).

Almost surely, 2^21252450 is an apocalyptic number.

21252450 is an abundant number, since it is smaller than the sum of its proper divisors (34235070).

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

21252450 is a wasteful number, since it uses less digits than its factorization.

21252450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7491 (or 7486 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 21252450 is about 4610.0379607982. The cubic root of 21252450 is about 276.9935572622.

Adding to 21252450 its reverse (5425212), we get a palindrome (26677662).

The spelling of 21252450 in words is "twenty-one million, two hundred fifty-two thousand, four hundred fifty".