1289999 has 4 divisors (see below), whose sum is σ = 1308240. Its totient is φ = 1271760.

The previous prime is 1289971. The next prime is 1290013. The reversal of 1289999 is 9999821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1289999 - 2¹² = 1285903 is a prime.

It is a Duffinian number.

1289999 is a modest number, since divided by 9999 gives 128 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1289969) 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, 9014 + ... + 9155.

It is an arithmetic number, because the mean of its divisors is an integer number (327060).

2^1289999 is an apocalyptic number.

1289999 is a deficient number, since it is larger than the sum of its proper divisors (18241).

1289999 is an equidigital number, since it uses as much as digits as its factorization.

1289999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18240.

The product of its digits is 104976, while the sum is 47.

The square root of 1289999 is about 1135.7812289345. The cubic root of 1289999 is about 108.8586952164.

The spelling of 1289999 in words is "one million, two hundred eighty-nine thousand, nine hundred ninety-nine".