1291218767 has 2 divisors, whose sum is σ = 1291218768. Its totient is φ = 1291218766.

The previous prime is 1291218763. The next prime is 1291218791. The reversal of 1291218767 is 7678121921.

It is a weak prime.

It is an emirp because it is prime and its reverse (7678121921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1291218767 - 2² = 1291218763 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1291218763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645609383 + 645609384.

It is an arithmetic number, because the mean of its divisors is an integer number (645609384).

Almost surely, 2^1291218767 is an apocalyptic number.

1291218767 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291218767 is an equidigital number, since it uses as much as digits as its factorization.

1291218767 is an evil number, because the sum of its binary digits is even.

The product of its digits is 84672, while the sum is 44.

The square root of 1291218767 is about 35933.5326262253. The cubic root of 1291218767 is about 1088.9299509185.

The spelling of 1291218767 in words is "one billion, two hundred ninety-one million, two hundred eighteen thousand, seven hundred sixty-seven".