21263353 has 2 divisors, whose sum is σ = 21263354. Its totient is φ = 21263352.

The previous prime is 21263309. The next prime is 21263357. The reversal of 21263353 is 35336212.

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., 21040569 + 222784 = 4587^2 + 472^2 .

It is a cyclic number.

It is not a de Polignac number, because 21263353 - 2⁹ = 21262841 is a prime.

It is not a weakly prime, because it can be changed into another prime (21263357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10631676 + 10631677.

It is an arithmetic number, because the mean of its divisors is an integer number (10631677).

Almost surely, 2^21263353 is an apocalyptic number.

It is an amenable number.

21263353 is a deficient number, since it is larger than the sum of its proper divisors (1).

21263353 is an equidigital number, since it uses as much as digits as its factorization.

21263353 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 25.

The square root of 21263353 is about 4611.2203373944. The cubic root of 21263353 is about 277.0409172050.

Adding to 21263353 its reverse (35336212), we get a palindrome (56599565).

The spelling of 21263353 in words is "twenty-one million, two hundred sixty-three thousand, three hundred fifty-three".