1331 has 4 divisors (see below), whose sum is σ = 1464. Its totient is φ = 1210.

The previous prime is 1327. The next prime is 1361.

It can be divided in two parts, 13 and 31, that added together give a palindrome (44).

1331 = T_{18} + T_{19} + ... +
T_{23}.

The cubic root of 1331 is 11.

It is a perfect power (a cube), and thus also a powerful number.

1331 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1331 - 2^{2} = 1327 is a prime.

It is a super-2 number, since 2×1331^{2} = 3543122, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 11 and base 16.

It is not an unprimeable number, because it can be changed into a prime (1301) 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, 116 + ... + 126.

It is an arithmetic number, because the mean of its divisors is an integer number (366).

1331 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1331 is the 20-th centered heptagonal number.

1331 is a deficient number, since it is larger than the sum of its proper divisors (133).

1331 is an frugal number, since it uses more digits than its factorization.

With its predecessor (1330) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (33).

1331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33 (or 11 counting only the distinct ones).

The product of its digits is 9, while the sum is 8.

The square root of 1331 is about 36.4828726939.

The spelling of 1331 in words is "one thousand, three hundred thirty-one".

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