1216622717 has 2 divisors, whose sum is σ = 1216622718. Its totient is φ = 1216622716.

The previous prime is 1216622689. The next prime is 1216622723. The reversal of 1216622717 is 7172266121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 920576281 + 296046436 = 30341^2 + 17206^2 .

It is a cyclic number.

It is not a de Polignac number, because 1216622717 - 2¹⁴ = 1216606333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1216622747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608311358 + 608311359.

It is an arithmetic number, because the mean of its divisors is an integer number (608311359).

Almost surely, 2^1216622717 is an apocalyptic number.

It is an amenable number.

1216622717 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216622717 is an equidigital number, since it uses as much as digits as its factorization.

1216622717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14112, while the sum is 35.

The square root of 1216622717 is about 34880.1192228467. The cubic root of 1216622717 is about 1067.5428278554.

Adding to 1216622717 its reverse (7172266121), we get a palindrome (8388888838).

The spelling of 1216622717 in words is "one billion, two hundred sixteen million, six hundred twenty-two thousand, seven hundred seventeen".