1247989 has 4 divisors (see below), whose sum is σ = 1277056. Its totient is φ = 1218924.

The previous prime is 1247969. The next prime is 1248001. The reversal of 1247989 is 9897421.

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, and also an emirpimes, since its reverse is a distinct semiprime: 9897421 = 1877 ⋅5273.

It is a cyclic number.

It is not a de Polignac number, because 1247989 - 2⁷ = 1247861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1247959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14469 + ... + 14554.

It is an arithmetic number, because the mean of its divisors is an integer number (319264).

2^1247989 is an apocalyptic number.

It is an amenable number.

1247989 is a deficient number, since it is larger than the sum of its proper divisors (29067).

1247989 is an equidigital number, since it uses as much as digits as its factorization.

1247989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29066.

The product of its digits is 36288, while the sum is 40.

The square root of 1247989 is about 1117.1342802009. The cubic root of 1247989 is about 107.6639359196.

The spelling of 1247989 in words is "one million, two hundred forty-seven thousand, nine hundred eighty-nine".