1285989 has 4 divisors (see below), whose sum is σ = 1714656. Its totient is φ = 857324.

The previous prime is 1285981. The next prime is 1285993. The reversal of 1285989 is 9895821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1285989 - 2³ = 1285981 is a prime.

It is a D-number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1285989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1285981) 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, 214329 + ... + 214334.

It is an arithmetic number, because the mean of its divisors is an integer number (428664).

2^1285989 is an apocalyptic number.

It is an amenable number.

1285989 is a deficient number, since it is larger than the sum of its proper divisors (428667).

1285989 is an equidigital number, since it uses as much as digits as its factorization.

1285989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428666.

The product of its digits is 51840, while the sum is 42.

The square root of 1285989 is about 1134.0145501712. The cubic root of 1285989 is about 108.7457813134.

The spelling of 1285989 in words is "one million, two hundred eighty-five thousand, nine hundred eighty-nine".