1281803 has 2 divisors, whose sum is σ = 1281804. Its totient is φ = 1281802.

The previous prime is 1281799. The next prime is 1281809. The reversal of 1281803 is 3081821.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1281803 - 2² = 1281799 is a prime.

It is not a weakly prime, because it can be changed into another prime (1281809) 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 as a sum of consecutive naturals, namely, 640901 + 640902.

It is an arithmetic number, because the mean of its divisors is an integer number (640902).

2^1281803 is an apocalyptic number.

1281803 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281803 is an equidigital number, since it uses as much as digits as its factorization.

1281803 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 1281803 is about 1132.1673904507. The cubic root of 1281803 is about 108.6276609016.

The spelling of 1281803 in words is "one million, two hundred eighty-one thousand, eight hundred three".