21000240307 has 2 divisors, whose sum is σ = 21000240308. Its totient is φ = 21000240306.

The previous prime is 21000240259. The next prime is 21000240319. The reversal of 21000240307 is 70304200012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21000240307 - 2¹⁹ = 20999716019 is a prime.

It is not a weakly prime, because it can be changed into another prime (21000240397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500120153 + 10500120154.

It is an arithmetic number, because the mean of its divisors is an integer number (10500120154).

Almost surely, 2^21000240307 is an apocalyptic number.

21000240307 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000240307 is an equidigital number, since it uses as much as digits as its factorization.

21000240307 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 19.

Adding to 21000240307 its reverse (70304200012), we get a palindrome (91304440319).

The spelling of 21000240307 in words is "twenty-one billion, two hundred forty thousand, three hundred seven".