11981131 has 2 divisors, whose sum is σ = 11981132. Its totient is φ = 11981130.

The previous prime is 11981117. The next prime is 11981161. The reversal of 11981131 is 13118911.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11981131 is a prime.

It is a super-2 number, since 2×11981131² = 287095000078322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 11981096 and 11981105.

It is not a weakly prime, because it can be changed into another prime (11981161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5990565 + 5990566.

It is an arithmetic number, because the mean of its divisors is an integer number (5990566).

Almost surely, 2^11981131 is an apocalyptic number.

11981131 is a deficient number, since it is larger than the sum of its proper divisors (1).

11981131 is an equidigital number, since it uses as much as digits as its factorization.

11981131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 25.

The square root of 11981131 is about 3461.3770381165. The cubic root of 11981131 is about 228.8227877099.

The spelling of 11981131 in words is "eleven million, nine hundred eighty-one thousand, one hundred thirty-one".