1243989 has 12 divisors (see below), whose sum is σ = 1824576. Its totient is φ = 816552.

The previous prime is 1243969. The next prime is 1243997. The reversal of 1243989 is 9893421.

It is not a de Polignac number, because 1243989 - 2⁹ = 1243477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243939) 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, 429 + ... + 1634.

It is an arithmetic number, because the mean of its divisors is an integer number (152048).

2^1243989 is an apocalyptic number.

It is an amenable number.

1243989 is a deficient number, since it is larger than the sum of its proper divisors (580587).

1243989 is a wasteful number, since it uses less digits than its factorization.

1243989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2136 (or 2133 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 1243989 is about 1115.3425482783. The cubic root of 1243989 is about 107.5487862211.

The spelling of 1243989 in words is "one million, two hundred forty-three thousand, nine hundred eighty-nine".