21413453 has 4 divisors (see below), whose sum is σ = 21423360. Its totient is φ = 21403548.

The previous prime is 21413449. The next prime is 21413459. The reversal of 21413453 is 35431412.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21413453 - 2² = 21413449 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 (21413459) 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, 173 + ... + 6546.

It is an arithmetic number, because the mean of its divisors is an integer number (5355840).

Almost surely, 2^21413453 is an apocalyptic number.

It is an amenable number.

21413453 is a deficient number, since it is larger than the sum of its proper divisors (9907).

21413453 is an equidigital number, since it uses as much as digits as its factorization.

21413453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9906.

The product of its digits is 1440, while the sum is 23.

The square root of 21413453 is about 4627.4672338116. The cubic root of 21413453 is about 277.6912752103.

Adding to 21413453 its reverse (35431412), we get a palindrome (56844865).

The spelling of 21413453 in words is "twenty-one million, four hundred thirteen thousand, four hundred fifty-three".