21115664683 has 2 divisors, whose sum is σ = 21115664684. Its totient is φ = 21115664682.

The previous prime is 21115664681. The next prime is 21115664771. The reversal of 21115664683 is 38646651112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21115664683 - 2¹ = 21115664681 is a prime.

Together with 21115664681, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21115664681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10557832341 + 10557832342.

It is an arithmetic number, because the mean of its divisors is an integer number (10557832342).

Almost surely, 2^21115664683 is an apocalyptic number.

21115664683 is a deficient number, since it is larger than the sum of its proper divisors (1).

21115664683 is an equidigital number, since it uses as much as digits as its factorization.

21115664683 is an evil number, because the sum of its binary digits is even.

The product of its digits is 207360, while the sum is 43.

The spelling of 21115664683 in words is "twenty-one billion, one hundred fifteen million, six hundred sixty-four thousand, six hundred eighty-three".