1216865017 has 2 divisors, whose sum is σ = 1216865018. Its totient is φ = 1216865016.

The previous prime is 1216864997. The next prime is 1216865033. The reversal of 1216865017 is 7105686121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1010540521 + 206324496 = 31789^2 + 14364^2 .

It is an emirp because it is prime and its reverse (7105686121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1216865017 - 2¹⁵ = 1216832249 is a prime.

It is not a weakly prime, because it can be changed into another prime (1216865717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608432508 + 608432509.

It is an arithmetic number, because the mean of its divisors is an integer number (608432509).

Almost surely, 2^1216865017 is an apocalyptic number.

It is an amenable number.

1216865017 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216865017 is an equidigital number, since it uses as much as digits as its factorization.

1216865017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 37.

The square root of 1216865017 is about 34883.5923752127. The cubic root of 1216865017 is about 1067.6136930063.

The spelling of 1216865017 in words is "one billion, two hundred sixteen million, eight hundred sixty-five thousand, seventeen".