21115404307 has 2 divisors, whose sum is σ = 21115404308. Its totient is φ = 21115404306.

The previous prime is 21115404283. The next prime is 21115404313. The reversal of 21115404307 is 70340451112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21115404307 - 2⁷ = 21115404179 is a prime.

It is not a weakly prime, because it can be changed into another prime (21115404337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10557702153 + 10557702154.

It is an arithmetic number, because the mean of its divisors is an integer number (10557702154).

Almost surely, 2^21115404307 is an apocalyptic number.

21115404307 is a deficient number, since it is larger than the sum of its proper divisors (1).

21115404307 is an equidigital number, since it uses as much as digits as its factorization.

21115404307 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 28.

Adding to 21115404307 its reverse (70340451112), we get a palindrome (91455855419).

The spelling of 21115404307 in words is "twenty-one billion, one hundred fifteen million, four hundred four thousand, three hundred seven".