1271916787 has 2 divisors, whose sum is σ = 1271916788. Its totient is φ = 1271916786.

The previous prime is 1271916769. The next prime is 1271916797. The reversal of 1271916787 is 7876191721.

It is a strong prime.

It is an emirp because it is prime and its reverse (7876191721) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1271916787 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1271916787.

It is not a weakly prime, because it can be changed into another prime (1271916707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 635958393 + 635958394.

It is an arithmetic number, because the mean of its divisors is an integer number (635958394).

Almost surely, 2^1271916787 is an apocalyptic number.

1271916787 is a deficient number, since it is larger than the sum of its proper divisors (1).

1271916787 is an equidigital number, since it uses as much as digits as its factorization.

1271916787 is an evil number, because the sum of its binary digits is even.

The product of its digits is 296352, while the sum is 49.

The square root of 1271916787 is about 35663.9423928427. The cubic root of 1271916787 is about 1083.4766753023.

The spelling of 1271916787 in words is "one billion, two hundred seventy-one million, nine hundred sixteen thousand, seven hundred eighty-seven".