21053353 has 2 divisors, whose sum is σ = 21053354. Its totient is φ = 21053352.

The previous prime is 21053323. The next prime is 21053381. The reversal of 21053353 is 35335012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17909824 + 3143529 = 4232^2 + 1773^2 .

It is a cyclic number.

It is not a de Polignac number, because 21053353 - 2⁹ = 21052841 is a prime.

It is not a weakly prime, because it can be changed into another prime (21053323) 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, 10526676 + 10526677.

It is an arithmetic number, because the mean of its divisors is an integer number (10526677).

Almost surely, 2^21053353 is an apocalyptic number.

It is an amenable number.

21053353 is a deficient number, since it is larger than the sum of its proper divisors (1).

21053353 is an equidigital number, since it uses as much as digits as its factorization.

21053353 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1350, while the sum is 22.

The square root of 21053353 is about 4588.3932917744. The cubic root of 21053353 is about 276.1258658923.

Adding to 21053353 its reverse (35335012), we get a palindrome (56388365).

The spelling of 21053353 in words is "twenty-one million, fifty-three thousand, three hundred fifty-three".