1271999671 has 2 divisors, whose sum is σ = 1271999672. Its totient is φ = 1271999670.

The previous prime is 1271999639. The next prime is 1271999699. The reversal of 1271999671 is 1769991721.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1271999671 - 2⁵ = 1271999639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1271999171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 635999835 + 635999836.

It is an arithmetic number, because the mean of its divisors is an integer number (635999836).

Almost surely, 2^1271999671 is an apocalyptic number.

1271999671 is a deficient number, since it is larger than the sum of its proper divisors (1).

1271999671 is an equidigital number, since it uses as much as digits as its factorization.

1271999671 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 428652, while the sum is 52.

The square root of 1271999671 is about 35665.1043879028. The cubic root of 1271999671 is about 1083.5002095804.

The spelling of 1271999671 in words is "one billion, two hundred seventy-one million, nine hundred ninety-nine thousand, six hundred seventy-one".