21245453 has 4 divisors (see below), whose sum is σ = 21264768. Its totient is φ = 21226140.

The previous prime is 21245417. The next prime is 21245459. The reversal of 21245453 is 35454212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21245453 - 2²² = 17051149 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 7901 + ... + 10242.

It is an arithmetic number, because the mean of its divisors is an integer number (5316192).

Almost surely, 2^21245453 is an apocalyptic number.

It is an amenable number.

21245453 is a deficient number, since it is larger than the sum of its proper divisors (19315).

21245453 is a wasteful number, since it uses less digits than its factorization.

21245453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19314.

The product of its digits is 4800, while the sum is 26.

The square root of 21245453 is about 4609.2790108649. The cubic root of 21245453 is about 276.9631554864.

Adding to 21245453 its reverse (35454212), we get a palindrome (56699665).

The spelling of 21245453 in words is "twenty-one million, two hundred forty-five thousand, four hundred fifty-three".