1287867 has 12 divisors (see below), whose sum is σ = 1997736. Its totient is φ = 735840.

The previous prime is 1287857. The next prime is 1287883. The reversal of 1287867 is 7687821.

It is not a de Polignac number, because 1287867 - 2⁷ = 1287739 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1287817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4234 + ... + 4527.

It is an arithmetic number, because the mean of its divisors is an integer number (166478).

2^1287867 is an apocalyptic number.

1287867 is a deficient number, since it is larger than the sum of its proper divisors (709869).

1287867 is an equidigital number, since it uses as much as digits as its factorization.

1287867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8778 (or 8771 counting only the distinct ones).

The product of its digits is 37632, while the sum is 39.

The square root of 1287867 is about 1134.8422797905. The cubic root of 1287867 is about 108.7986913680.

The spelling of 1287867 in words is "one million, two hundred eighty-seven thousand, eight hundred sixty-seven".