1271257812667 has 2 divisors, whose sum is σ = 1271257812668. Its totient is φ = 1271257812666.

The previous prime is 1271257812637. The next prime is 1271257812679. The reversal of 1271257812667 is 7662187521721.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1271257812667 is a prime.

It is not a weakly prime, because it can be changed into another prime (1271257812637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 635628906333 + 635628906334.

It is an arithmetic number, because the mean of its divisors is an integer number (635628906334).

Almost surely, 2^{1271257812667} is an apocalyptic number.

1271257812667 is a deficient number, since it is larger than the sum of its proper divisors (1).

1271257812667 is an equidigital number, since it uses as much as digits as its factorization.

1271257812667 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3951360, while the sum is 55.

The spelling of 1271257812667 in words is "one trillion, two hundred seventy-one billion, two hundred fifty-seven million, eight hundred twelve thousand, six hundred sixty-seven".