21300312643 has 2 divisors, whose sum is σ = 21300312644. Its totient is φ = 21300312642.

The previous prime is 21300312611. The next prime is 21300312647. The reversal of 21300312643 is 34621300312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21300312643 - 2⁵ = 21300312611 is a prime.

It is not a weakly prime, because it can be changed into another prime (21300312647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10650156321 + 10650156322.

It is an arithmetic number, because the mean of its divisors is an integer number (10650156322).

Almost surely, 2^21300312643 is an apocalyptic number.

21300312643 is a deficient number, since it is larger than the sum of its proper divisors (1).

21300312643 is an equidigital number, since it uses as much as digits as its factorization.

21300312643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 25.

Adding to 21300312643 its reverse (34621300312), we get a palindrome (55921612955).

The spelling of 21300312643 in words is "twenty-one billion, three hundred million, three hundred twelve thousand, six hundred forty-three".