1311181 has 2 divisors, whose sum is σ = 1311182. Its totient is φ = 1311180.

The previous prime is 1311173. The next prime is 1311217. The reversal of 1311181 is 1811131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1177225 + 133956 = 1085^2 + 366^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311181 - 2³ = 1311173 is a prime.

It is a super-2 number, since 2×1311181² = 3438391229522, which contains 22 as substring.

1311181 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1311131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655590 + 655591.

It is an arithmetic number, because the mean of its divisors is an integer number (655591).

2^1311181 is an apocalyptic number.

It is an amenable number.

1311181 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311181 is an equidigital number, since it uses as much as digits as its factorization.

1311181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24, while the sum is 16.

The square root of 1311181 is about 1145.0681202444. The cubic root of 1311181 is about 109.4512894693.

The spelling of 1311181 in words is "one million, three hundred eleven thousand, one hundred eighty-one".