1131 has 8 divisors (see below), whose sum is σ = 1680. Its totient is φ = 672.

The previous prime is 1129. The next prime is 1151. The reversal of 1131 is 1311.

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

1131 is nontrivially palindromic in base 11.

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

It is not a de Polignac number, because 1131 - 2^{1} = 1129 is a prime.

It is a super-2 number, since 2×1131^{2} = 2558322, which contains 22 as substring.

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.

1131 is an undulating number in base 11.

It is a plaindrome in base 14 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25 + ... + 53.

It is an arithmetic number, because the mean of its divisors is an integer number (210).

1131 is a deficient number, since it is larger than the sum of its proper divisors (549).

1131 is a wasteful number, since it uses less digits than its factorization.

1131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45.

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

The square root of 1131 is about 33.6303434416. The cubic root of 1131 is about 10.4188759758.

The spelling of 1131 in words is "one thousand, one hundred thirty-one".

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