216331979 has 2 divisors, whose sum is σ = 216331980. Its totient is φ = 216331978.

The previous prime is 216331957. The next prime is 216332071. The reversal of 216331979 is 979133612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216331979 - 2⁸ = 216331723 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (216331939) 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, 108165989 + 108165990.

It is an arithmetic number, because the mean of its divisors is an integer number (108165990).

Almost surely, 2^216331979 is an apocalyptic number.

216331979 is a deficient number, since it is larger than the sum of its proper divisors (1).

216331979 is an equidigital number, since it uses as much as digits as its factorization.

216331979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 61236, while the sum is 41.

The square root of 216331979 is about 14708.2282753566. The cubic root of 216331979 is about 600.3072306184.

The spelling of 216331979 in words is "two hundred sixteen million, three hundred thirty-one thousand, nine hundred seventy-nine".