21211453 has 4 divisors (see below), whose sum is σ = 21220668. Its totient is φ = 21202240.

The previous prime is 21211433. The next prime is 21211481. The reversal of 21211453 is 35411212.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 17960644 + 3250809 = 4238^2 + 1803^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21211453 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21211453.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2133 + ... + 6853.

It is an arithmetic number, because the mean of its divisors is an integer number (5305167).

Almost surely, 2^21211453 is an apocalyptic number.

It is an amenable number.

21211453 is a deficient number, since it is larger than the sum of its proper divisors (9215).

21211453 is an equidigital number, since it uses as much as digits as its factorization.

21211453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9214.

The product of its digits is 240, while the sum is 19.

The square root of 21211453 is about 4605.5893216829. The cubic root of 21211453 is about 276.8153313050.

Adding to 21211453 its reverse (35411212), we get a palindrome (56622665).

The spelling of 21211453 in words is "twenty-one million, two hundred eleven thousand, four hundred fifty-three".