131115811 has 4 divisors (see below), whose sum is σ = 132911992. Its totient is φ = 129319632.

The previous prime is 131115769. The next prime is 131115823. The reversal of 131115811 is 118511131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 118511131 = 17 ⋅6971243.

It is a cyclic number.

It is not a de Polignac number, because 131115811 - 2⁷ = 131115683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131115011) 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, 897981 + ... + 898126.

It is an arithmetic number, because the mean of its divisors is an integer number (33227998).

Almost surely, 2^131115811 is an apocalyptic number.

131115811 is a deficient number, since it is larger than the sum of its proper divisors (1796181).

131115811 is an equidigital number, since it uses as much as digits as its factorization.

131115811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1796180.

The product of its digits is 120, while the sum is 22.

The square root of 131115811 is about 11450.5812516221. The cubic root of 131115811 is about 508.0249267017.

Adding to 131115811 its reverse (118511131), we get a palindrome (249626942).

The spelling of 131115811 in words is "one hundred thirty-one million, one hundred fifteen thousand, eight hundred eleven".