1216329797 has 2 divisors, whose sum is σ = 1216329798. Its totient is φ = 1216329796.

The previous prime is 1216329773. The next prime is 1216329799. The reversal of 1216329797 is 7979236121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 830246596 + 386083201 = 28814^2 + 19649^2 .

It is an emirp because it is prime and its reverse (7979236121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1216329797 - 2²⁸ = 947894341 is a prime.

It is a super-3 number, since 3×1216329797³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 1216329799, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1216329799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608164898 + 608164899.

It is an arithmetic number, because the mean of its divisors is an integer number (608164899).

Almost surely, 2^1216329797 is an apocalyptic number.

It is an amenable number.

1216329797 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216329797 is an equidigital number, since it uses as much as digits as its factorization.

1216329797 is an evil number, because the sum of its binary digits is even.

The product of its digits is 285768, while the sum is 47.

The square root of 1216329797 is about 34875.9200165386. The cubic root of 1216329797 is about 1067.4571453782.

The spelling of 1216329797 in words is "one billion, two hundred sixteen million, three hundred twenty-nine thousand, seven hundred ninety-seven".