1311555 has 16 divisors (see below), whose sum is σ = 2398464. Its totient is φ = 599520.

The previous prime is 1311553. The next prime is 1311559. The reversal of 1311555 is 5551131.

It is not a de Polignac number, because 1311555 - 2¹ = 1311553 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (1311553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6141 + ... + 6350.

It is an arithmetic number, because the mean of its divisors is an integer number (149904).

2^1311555 is an apocalyptic number.

1311555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1311555 is a deficient number, since it is larger than the sum of its proper divisors (1086909).

1311555 is a wasteful number, since it uses less digits than its factorization.

1311555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12506.

The product of its digits is 375, while the sum is 21.

The square root of 1311555 is about 1145.2314176620. The cubic root of 1311555 is about 109.4616950733.

Adding to 1311555 its reverse (5551131), we get a palindrome (6862686).

The spelling of 1311555 in words is "one million, three hundred eleven thousand, five hundred fifty-five".