216986687 has 2 divisors, whose sum is σ = 216986688. Its totient is φ = 216986686.

The previous prime is 216986681. The next prime is 216986711. The reversal of 216986687 is 786689612.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216986687 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216986681) 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, 108493343 + 108493344.

It is an arithmetic number, because the mean of its divisors is an integer number (108493344).

Almost surely, 2^216986687 is an apocalyptic number.

216986687 is a deficient number, since it is larger than the sum of its proper divisors (1).

216986687 is an equidigital number, since it uses as much as digits as its factorization.

216986687 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1741824, while the sum is 53.

The square root of 216986687 is about 14730.4679830615. The cubic root of 216986687 is about 600.9122114882.

The spelling of 216986687 in words is "two hundred sixteen million, nine hundred eighty-six thousand, six hundred eighty-seven".