1261216267 has 2 divisors, whose sum is σ = 1261216268. Its totient is φ = 1261216266.

The previous prime is 1261216217. The next prime is 1261216303. The reversal of 1261216267 is 7626121621.

It is a strong prime.

It is an emirp because it is prime and its reverse (7626121621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1261216267 - 2¹¹ = 1261214219 is a prime.

It is not a weakly prime, because it can be changed into another prime (1261216217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630608133 + 630608134.

It is an arithmetic number, because the mean of its divisors is an integer number (630608134).

Almost surely, 2^1261216267 is an apocalyptic number.

1261216267 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261216267 is an equidigital number, since it uses as much as digits as its factorization.

1261216267 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 34.

The square root of 1261216267 is about 35513.6067866952. The cubic root of 1261216267 is about 1080.4297178300.

Adding to 1261216267 its reverse (7626121621), we get a palindrome (8887337888).

The spelling of 1261216267 in words is "one billion, two hundred sixty-one million, two hundred sixteen thousand, two hundred sixty-seven".