21303109 has 2 divisors, whose sum is σ = 21303110. Its totient is φ = 21303108.

The previous prime is 21303059. The next prime is 21303127. The reversal of 21303109 is 90130312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10870209 + 10432900 = 3297^2 + 3230^2 .

It is a cyclic number.

It is not a de Polignac number, because 21303109 - 2⁹ = 21302597 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21303209) 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, 10651554 + 10651555.

It is an arithmetic number, because the mean of its divisors is an integer number (10651555).

Almost surely, 2^21303109 is an apocalyptic number.

It is an amenable number.

21303109 is a deficient number, since it is larger than the sum of its proper divisors (1).

21303109 is an equidigital number, since it uses as much as digits as its factorization.

21303109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162, while the sum is 19.

The square root of 21303109 is about 4615.5291137637. The cubic root of 21303109 is about 277.2134704475.

It can be divided in two parts, 21303 and 109, that added together give a palindrome (21412).

The spelling of 21303109 in words is "twenty-one million, three hundred three thousand, one hundred nine".