1312111217 has 2 divisors, whose sum is σ = 1312111218. Its totient is φ = 1312111216.

The previous prime is 1312111201. The next prime is 1312111249. The reversal of 1312111217 is 7121112131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 986525281 + 325585936 = 31409^2 + 18044^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312111217 - 2⁴ = 1312111201 is a prime.

It is not a weakly prime, because it can be changed into another prime (1312111277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656055608 + 656055609.

It is an arithmetic number, because the mean of its divisors is an integer number (656055609).

Almost surely, 2^1312111217 is an apocalyptic number.

It is an amenable number.

1312111217 is a deficient number, since it is larger than the sum of its proper divisors (1).

1312111217 is an equidigital number, since it uses as much as digits as its factorization.

1312111217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 84, while the sum is 20.

The square root of 1312111217 is about 36223.0757528954. The cubic root of 1312111217 is about 1094.7716674648.

Adding to 1312111217 its reverse (7121112131), we get a palindrome (8433223348).

The spelling of 1312111217 in words is "one billion, three hundred twelve million, one hundred eleven thousand, two hundred seventeen".