11143981 has 2 divisors, whose sum is σ = 11143982. Its totient is φ = 11143980.

The previous prime is 11143967. The next prime is 11143997. The reversal of 11143981 is 18934111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5597956 + 5546025 = 2366^2 + 2355^2 .

It is a cyclic number.

It is not a de Polignac number, because 11143981 - 2⁵ = 11143949 is a prime.

It is a super-2 number, since 2×11143981² = 248376625056722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11143901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5571990 + 5571991.

It is an arithmetic number, because the mean of its divisors is an integer number (5571991).

Almost surely, 2^11143981 is an apocalyptic number.

It is an amenable number.

11143981 is a deficient number, since it is larger than the sum of its proper divisors (1).

11143981 is an equidigital number, since it uses as much as digits as its factorization.

11143981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 28.

The square root of 11143981 is about 3338.2601756005. The cubic root of 11143981 is about 223.3641419343.

The spelling of 11143981 in words is "eleven million, one hundred forty-three thousand, nine hundred eighty-one".