21053323 has 2 divisors, whose sum is σ = 21053324. Its totient is φ = 21053322.

The previous prime is 21053299. The next prime is 21053353. The reversal of 21053323 is 32335012.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21053323 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21053323.

It is not a weakly prime, because it can be changed into another prime (21053353) 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 as a sum of consecutive naturals, namely, 10526661 + 10526662.

It is an arithmetic number, because the mean of its divisors is an integer number (10526662).

Almost surely, 2^21053323 is an apocalyptic number.

21053323 is a deficient number, since it is larger than the sum of its proper divisors (1).

21053323 is an equidigital number, since it uses as much as digits as its factorization.

21053323 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 540, while the sum is 19.

The square root of 21053323 is about 4588.3900226550. The cubic root of 21053323 is about 276.1257347370.

Adding to 21053323 its reverse (32335012), we get a palindrome (53388335).

The spelling of 21053323 in words is "twenty-one million, fifty-three thousand, three hundred twenty-three".