218116831 has 2 divisors, whose sum is σ = 218116832. Its totient is φ = 218116830.

The previous prime is 218116807. The next prime is 218116841. The reversal of 218116831 is 138611812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 218116831 - 2⁵ = 218116799 is a prime.

It is a super-2 number, since 2×218116831² = 95149903930965122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 218116793 and 218116802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218116841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109058415 + 109058416.

It is an arithmetic number, because the mean of its divisors is an integer number (109058416).

Almost surely, 2^218116831 is an apocalyptic number.

218116831 is a deficient number, since it is larger than the sum of its proper divisors (1).

218116831 is an equidigital number, since it uses as much as digits as its factorization.

218116831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2304, while the sum is 31.

The square root of 218116831 is about 14768.7789271828. The cubic root of 218116831 is about 601.9536604839.

The spelling of 218116831 in words is "two hundred eighteen million, one hundred sixteen thousand, eight hundred thirty-one".