21044263 has 2 divisors, whose sum is σ = 21044264. Its totient is φ = 21044262.

The previous prime is 21044251. The next prime is 21044269. The reversal of 21044263 is 36244012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21044263 is a prime.

It is a super-2 number, since 2×21044263² = 885722010426338, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21044269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10522131 + 10522132.

It is an arithmetic number, because the mean of its divisors is an integer number (10522132).

Almost surely, 2^21044263 is an apocalyptic number.

21044263 is a deficient number, since it is larger than the sum of its proper divisors (1).

21044263 is an equidigital number, since it uses as much as digits as its factorization.

21044263 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 21044263 is about 4587.4026420187. The cubic root of 21044263 is about 276.0861201181.

Adding to 21044263 its reverse (36244012), we get a palindrome (57288275).

The spelling of 21044263 in words is "twenty-one million, forty-four thousand, two hundred sixty-three".