1311603 has 4 divisors (see below), whose sum is σ = 1748808. Its totient is φ = 874400.

The previous prime is 1311599. The next prime is 1311617. The reversal of 1311603 is 3061131.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1311603 - 2² = 1311599 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (1311623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 218598 + ... + 218603.

It is an arithmetic number, because the mean of its divisors is an integer number (437202).

2^1311603 is an apocalyptic number.

1311603 is a deficient number, since it is larger than the sum of its proper divisors (437205).

1311603 is an equidigital number, since it uses as much as digits as its factorization.

1311603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 437204.

The product of its (nonzero) digits is 54, while the sum is 15.

The square root of 1311603 is about 1145.2523739334. The cubic root of 1311603 is about 109.4630304087.

Adding to 1311603 its reverse (3061131), we get a palindrome (4372734).

The spelling of 1311603 in words is "one million, three hundred eleven thousand, six hundred three".