21040463 has 2 divisors, whose sum is σ = 21040464. Its totient is φ = 21040462.

The previous prime is 21040447. The next prime is 21040489. The reversal of 21040463 is 36404012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21040463 - 2⁴ = 21040447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21040493) 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, 10520231 + 10520232.

It is an arithmetic number, because the mean of its divisors is an integer number (10520232).

Almost surely, 2^21040463 is an apocalyptic number.

21040463 is a deficient number, since it is larger than the sum of its proper divisors (1).

21040463 is an equidigital number, since it uses as much as digits as its factorization.

21040463 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 21040463 is about 4586.9884455926. The cubic root of 21040463 is about 276.0695013305.

Adding to 21040463 its reverse (36404012), we get a palindrome (57444475).

The spelling of 21040463 in words is "twenty-one million, forty thousand, four hundred sixty-three".