1281985 has 8 divisors (see below), whose sum is σ = 1552680. Its totient is φ = 1016064.

The previous prime is 1281983. The next prime is 1282007. The reversal of 1281985 is 5891821.

It can be written as a sum of positive squares in 4 ways, for example, as 106929 + 1175056 = 327^2 + 1084^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1281985 - 2¹ = 1281983 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1281985.

It is not an unprimeable number, because it can be changed into a prime (1281983) 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 7 ways as a sum of consecutive naturals, for example, 570 + ... + 1699.

It is an arithmetic number, because the mean of its divisors is an integer number (194085).

2^1281985 is an apocalyptic number.

It is an amenable number.

1281985 is a deficient number, since it is larger than the sum of its proper divisors (270695).

1281985 is a wasteful number, since it uses less digits than its factorization.

1281985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2387.

The product of its digits is 5760, while the sum is 34.

The square root of 1281985 is about 1132.2477644049. The cubic root of 1281985 is about 108.6328019149.

The spelling of 1281985 in words is "one million, two hundred eighty-one thousand, nine hundred eighty-five".