11191381 has 2 divisors, whose sum is σ = 11191382. Its totient is φ = 11191380.

The previous prime is 11191351. The next prime is 11191429. The reversal of 11191381 is 18319111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5924356 + 5267025 = 2434^2 + 2295^2 .

It is a cyclic number.

It is not a de Polignac number, because 11191381 - 2¹¹ = 11189333 is a prime.

It is a super-2 number, since 2×11191381² = 250494017374322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11191331) 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, 5595690 + 5595691.

It is an arithmetic number, because the mean of its divisors is an integer number (5595691).

Almost surely, 2^11191381 is an apocalyptic number.

It is an amenable number.

11191381 is a deficient number, since it is larger than the sum of its proper divisors (1).

11191381 is an equidigital number, since it uses as much as digits as its factorization.

11191381 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 11191381 is about 3345.3521488776. The cubic root of 11191381 is about 223.6803809497.

It can be divided in two parts, 1119 and 1381, that added together give a square (2500 = 50²).

The spelling of 11191381 in words is "eleven million, one hundred ninety-one thousand, three hundred eighty-one".