21303481 has 2 divisors, whose sum is σ = 21303482. Its totient is φ = 21303480.

The previous prime is 21303473. The next prime is 21303511. The reversal of 21303481 is 18430312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11594025 + 9709456 = 3405^2 + 3116^2 .

It is a cyclic number.

It is not a de Polignac number, because 21303481 - 2³ = 21303473 is a prime.

It is a super-2 number, since 2×21303481² = 907676605434722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21303421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10651740 + 10651741.

It is an arithmetic number, because the mean of its divisors is an integer number (10651741).

Almost surely, 2^21303481 is an apocalyptic number.

It is an amenable number.

21303481 is a deficient number, since it is larger than the sum of its proper divisors (1).

21303481 is an equidigital number, since it uses as much as digits as its factorization.

21303481 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 21303481 is about 4615.5694123261. The cubic root of 21303481 is about 277.2150840275.

Adding to 21303481 its reverse (18430312), we get a palindrome (39733793).

The spelling of 21303481 in words is "twenty-one million, three hundred three thousand, four hundred eighty-one".