21051353 has 2 divisors, whose sum is σ = 21051354. Its totient is φ = 21051352.

The previous prime is 21051343. The next prime is 21051383. The reversal of 21051353 is 35315012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13053769 + 7997584 = 3613^2 + 2828^2 .

It is a cyclic number.

It is not a de Polignac number, because 21051353 - 2⁴ = 21051337 is a prime.

It is not a weakly prime, because it can be changed into another prime (21051323) 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, 10525676 + 10525677.

It is an arithmetic number, because the mean of its divisors is an integer number (10525677).

Almost surely, 2^21051353 is an apocalyptic number.

It is an amenable number.

21051353 is a deficient number, since it is larger than the sum of its proper divisors (1).

21051353 is an equidigital number, since it uses as much as digits as its factorization.

21051353 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 450, while the sum is 20.

The square root of 21051353 is about 4588.1753453851. The cubic root of 21051353 is about 276.1171219293.

Adding to 21051353 its reverse (35315012), we get a palindrome (56366365).

The spelling of 21051353 in words is "twenty-one million, fifty-one thousand, three hundred fifty-three".