1287998 has 8 divisors (see below), whose sum is σ = 1941192. Its totient is φ = 640936.

The previous prime is 1287997. The next prime is 1288003. The reversal of 1287998 is 8997821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287997) 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 3 ways as a sum of consecutive naturals, for example, 965 + ... + 1872.

It is an arithmetic number, because the mean of its divisors is an integer number (242649).

2^1287998 is an apocalyptic number.

1287998 is a deficient number, since it is larger than the sum of its proper divisors (653194).

1287998 is a wasteful number, since it uses less digits than its factorization.

1287998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3066.

The product of its digits is 72576, while the sum is 44.

The square root of 1287998 is about 1134.8999955943. The cubic root of 1287998 is about 108.8023801923.

The spelling of 1287998 in words is "one million, two hundred eighty-seven thousand, nine hundred ninety-eight".