216957911 has 2 divisors, whose sum is σ = 216957912. Its totient is φ = 216957910.

The previous prime is 216957889. The next prime is 216957913. The reversal of 216957911 is 119759612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216957911 - 2¹⁸ = 216695767 is a prime.

Together with 216957913, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216957913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108478955 + 108478956.

It is an arithmetic number, because the mean of its divisors is an integer number (108478956).

Almost surely, 2^216957911 is an apocalyptic number.

216957911 is a deficient number, since it is larger than the sum of its proper divisors (1).

216957911 is an equidigital number, since it uses as much as digits as its factorization.

216957911 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34020, while the sum is 41.

The square root of 216957911 is about 14729.4911996308. The cubic root of 216957911 is about 600.8856467029.

The spelling of 216957911 in words is "two hundred sixteen million, nine hundred fifty-seven thousand, nine hundred eleven".