1281187 has 2 divisors, whose sum is σ = 1281188. Its totient is φ = 1281186.

The previous prime is 1281167. The next prime is 1281193. The reversal of 1281187 is 7811821.

It is a strong prime.

It is an emirp because it is prime and its reverse (7811821) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1281187 is a prime.

It is not a weakly prime, because it can be changed into another prime (1281157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640593 + 640594.

It is an arithmetic number, because the mean of its divisors is an integer number (640594).

2^1281187 is an apocalyptic number.

1281187 is the 654-th hex number.

1281187 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281187 is an equidigital number, since it uses as much as digits as its factorization.

1281187 is an evil number, because the sum of its binary digits is even.

The product of its digits is 896, while the sum is 28.

The square root of 1281187 is about 1131.8953131805. The cubic root of 1281187 is about 108.6102569373.

The spelling of 1281187 in words is "one million, two hundred eighty-one thousand, one hundred eighty-seven".