1281655 has 8 divisors (see below), whose sum is σ = 1591200. Its totient is φ = 989856.

The previous prime is 1281653. The next prime is 1281667. The reversal of 1281655 is 5561821.

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 1281655 - 2¹ = 1281653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281653) 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 7 ways as a sum of consecutive naturals, for example, 4275 + ... + 4564.

It is an arithmetic number, because the mean of its divisors is an integer number (198900).

2^1281655 is an apocalyptic number.

1281655 is a deficient number, since it is larger than the sum of its proper divisors (309545).

1281655 is an equidigital number, since it uses as much as digits as its factorization.

1281655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8873.

The product of its digits is 2400, while the sum is 28.

The square root of 1281655 is about 1132.1020272043. The cubic root of 1281655 is about 108.6234799386.

It can be divided in two parts, 1281 and 655, that added together give a square (1936 = 44²).

The spelling of 1281655 in words is "one million, two hundred eighty-one thousand, six hundred fifty-five".