1289855 has 16 divisors (see below), whose sum is σ = 1788480. Its totient is φ = 874752.

The previous prime is 1289851. The next prime is 1289867. The reversal of 1289855 is 5589821.

It is a cyclic number.

It is not a de Polignac number, because 1289855 - 2² = 1289851 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1289851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4661 + ... + 4929.

It is an arithmetic number, because the mean of its divisors is an integer number (111780).

2^1289855 is an apocalyptic number.

1289855 is a deficient number, since it is larger than the sum of its proper divisors (498625).

1289855 is a wasteful number, since it uses less digits than its factorization.

1289855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418.

The product of its digits is 28800, while the sum is 38.

The square root of 1289855 is about 1135.7178346755. The cubic root of 1289855 is about 108.8546445064.

The spelling of 1289855 in words is "one million, two hundred eighty-nine thousand, eight hundred fifty-five".