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1311 = 31923

1311 has 8 divisors (see below), whose sum is σ = 1920. Its totient is φ = 792.

The previous prime is 1307. The next prime is 1319. The reversal of 1311 is 1131.

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

It is not a de Polignac number, because 1311 - 22 = 1307 is a prime.

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is an Ulam number.

It is a plaindrome in base 13 and base 14.

It is a nialpdrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 1311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1319) 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 7 ways as a sum of consecutive naturals, for example, 46 + ... + 68.

It is an arithmetic number, because the mean of its divisors is an integer number (240).

1311 is a deficient number, since it is larger than the sum of its proper divisors (609).

1311 is a wasteful number, since it uses less digits than its factorization.

1311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45.

The product of its digits is 3, while the sum is 6.

The square root of 1311 is about 36.2077339805. The cubic root of 1311 is about 10.9446252892.

Adding to 1311 its reverse (1131), we get a palindrome (2442).

The spelling of 1311 in words is "one thousand, three hundred eleven", and thus it is an iban number.

Divisors: 1 3 19 23 57 69 437 1311