216617939 has 2 divisors, whose sum is σ = 216617940. Its totient is φ = 216617938.

The previous prime is 216617923. The next prime is 216617957. The reversal of 216617939 is 939716612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216617939 - 2⁴ = 216617923 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 216617939.

It is not a weakly prime, because it can be changed into another prime (216617909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108308969 + 108308970.

It is an arithmetic number, because the mean of its divisors is an integer number (108308970).

Almost surely, 2^216617939 is an apocalyptic number.

216617939 is a deficient number, since it is larger than the sum of its proper divisors (1).

216617939 is an equidigital number, since it uses as much as digits as its factorization.

216617939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 122472, while the sum is 44.

The square root of 216617939 is about 14717.9461542703. The cubic root of 216617939 is about 600.5716209836.

The spelling of 216617939 in words is "two hundred sixteen million, six hundred seventeen thousand, nine hundred thirty-nine".