1287918 has 12 divisors (see below), whose sum is σ = 2790528. Its totient is φ = 429300.

The previous prime is 1287917. The next prime is 1287947. The reversal of 1287918 is 8197821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287917) 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 5 ways as a sum of consecutive naturals, for example, 35758 + ... + 35793.

It is an arithmetic number, because the mean of its divisors is an integer number (232544).

2^1287918 is an apocalyptic number.

1287918 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1287918 is an abundant number, since it is smaller than the sum of its proper divisors (1502610).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1287918 is a wasteful number, since it uses less digits than its factorization.

1287918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71559 (or 71556 counting only the distinct ones).

The product of its digits is 8064, while the sum is 36.

The square root of 1287918 is about 1134.8647496508. The cubic root of 1287918 is about 108.8001275049.

Subtracting 1287918 from its reverse (8197821), we obtain a triangular number (6909903 = T₃₇₁₇).

The spelling of 1287918 in words is "one million, two hundred eighty-seven thousand, nine hundred eighteen".