21330311287 has 2 divisors, whose sum is σ = 21330311288. Its totient is φ = 21330311286.

The previous prime is 21330311279. The next prime is 21330311323. The reversal of 21330311287 is 78211303312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21330311287 - 2³ = 21330311279 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21330311257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10665155643 + 10665155644.

It is an arithmetic number, because the mean of its divisors is an integer number (10665155644).

Almost surely, 2^21330311287 is an apocalyptic number.

21330311287 is a deficient number, since it is larger than the sum of its proper divisors (1).

21330311287 is an equidigital number, since it uses as much as digits as its factorization.

21330311287 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 31.

Adding to 21330311287 its reverse (78211303312), we get a palindrome (99541614599).

The spelling of 21330311287 in words is "twenty-one billion, three hundred thirty million, three hundred eleven thousand, two hundred eighty-seven".