1271987 has 2 divisors, whose sum is σ = 1271988. Its totient is φ = 1271986.

The previous prime is 1271971. The next prime is 1271999. The reversal of 1271987 is 7891721.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1271987 - 2⁴ = 1271971 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1271927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 635993 + 635994.

It is an arithmetic number, because the mean of its divisors is an integer number (635994).

2^1271987 is an apocalyptic number.

1271987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1271987 is an equidigital number, since it uses as much as digits as its factorization.

1271987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7056, while the sum is 35.

The square root of 1271987 is about 1127.8240110939. The cubic root of 1271987 is about 108.3496611813.

The spelling of 1271987 in words is "one million, two hundred seventy-one thousand, nine hundred eighty-seven".