21541453 has 2 divisors, whose sum is σ = 21541454. Its totient is φ = 21541452.

The previous prime is 21541451. The next prime is 21541477. The reversal of 21541453 is 35414512.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16621929 + 4919524 = 4077^2 + 2218^2 .

It is a cyclic number.

It is not a de Polignac number, because 21541453 - 2¹ = 21541451 is a prime.

Together with 21541451, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21541451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10770726 + 10770727.

It is an arithmetic number, because the mean of its divisors is an integer number (10770727).

Almost surely, 2^21541453 is an apocalyptic number.

It is an amenable number.

21541453 is a deficient number, since it is larger than the sum of its proper divisors (1).

21541453 is an equidigital number, since it uses as much as digits as its factorization.

21541453 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2400, while the sum is 25.

The square root of 21541453 is about 4641.2770871819. The cubic root of 21541453 is about 278.2434809429.

Adding to 21541453 its reverse (35414512), we get a palindrome (56955965).

The spelling of 21541453 in words is "twenty-one million, five hundred forty-one thousand, four hundred fifty-three".