1285609 has 4 divisors (see below), whose sum is σ = 1384516. Its totient is φ = 1186704.

The previous prime is 1285607. The next prime is 1285619. The reversal of 1285609 is 9065821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9065821 = 2399 ⋅3779.

It can be written as a sum of positive squares in 2 ways, for example, as 291600 + 994009 = 540^2 + 997^2 .

It is a cyclic number.

It is not a de Polignac number, because 1285609 - 2¹ = 1285607 is a prime.

It is a Duffinian number.

1285609 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1285607) 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, 49434 + ... + 49459.

It is an arithmetic number, because the mean of its divisors is an integer number (346129).

2^1285609 is an apocalyptic number.

It is an amenable number.

1285609 is a deficient number, since it is larger than the sum of its proper divisors (98907).

1285609 is an equidigital number, since it uses as much as digits as its factorization.

1285609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98906.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 1285609 is about 1133.8469914411. The cubic root of 1285609 is about 108.7350690736.

The spelling of 1285609 in words is "one million, two hundred eighty-five thousand, six hundred nine".