216505764679 has 2 divisors, whose sum is σ = 216505764680. Its totient is φ = 216505764678.

The previous prime is 216505764677. The next prime is 216505764701. The reversal of 216505764679 is 976467505612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216505764679 - 2¹ = 216505764677 is a prime.

It is a super-2 number, since 2×216505764679² (a number of 23 digits) contains 22 as substring.

Together with 216505764677, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216505764677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108252882339 + 108252882340.

It is an arithmetic number, because the mean of its divisors is an integer number (108252882340).

Almost surely, 2^216505764679 is an apocalyptic number.

216505764679 is a deficient number, since it is larger than the sum of its proper divisors (1).

216505764679 is an equidigital number, since it uses as much as digits as its factorization.

216505764679 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19051200, while the sum is 58.

The spelling of 216505764679 in words is "two hundred sixteen billion, five hundred five million, seven hundred sixty-four thousand, six hundred seventy-nine".