11511391 has 2 divisors, whose sum is σ = 11511392. Its totient is φ = 11511390.

The previous prime is 11511389. The next prime is 11511413. The reversal of 11511391 is 19311511.

It is an a-pointer prime, because the next prime (11511413) can be obtained adding 11511391 to its sum of digits (22).

It is a weak prime.

It is an emirp because it is prime and its reverse (19311511) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11511391 - 2¹ = 11511389 is a prime.

Together with 11511389, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11511341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5755695 + 5755696.

It is an arithmetic number, because the mean of its divisors is an integer number (5755696).

Almost surely, 2^11511391 is an apocalyptic number.

11511391 is a deficient number, since it is larger than the sum of its proper divisors (1).

11511391 is an equidigital number, since it uses as much as digits as its factorization.

11511391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 135, while the sum is 22.

The square root of 11511391 is about 3392.8440871929. The cubic root of 11511391 is about 225.7923733336.

The spelling of 11511391 in words is "eleven million, five hundred eleven thousand, three hundred ninety-one".