11521591 has 2 divisors, whose sum is σ = 11521592. Its totient is φ = 11521590.

The previous prime is 11521589. The next prime is 11521603. The reversal of 11521591 is 19512511.

It is a happy number.

11521591 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is an emirp because it is prime and its reverse (19512511) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11521591 - 2¹ = 11521589 is a prime.

Together with 11521589, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11521501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5760795 + 5760796.

It is an arithmetic number, because the mean of its divisors is an integer number (5760796).

Almost surely, 2^11521591 is an apocalyptic number.

11521591 is a deficient number, since it is larger than the sum of its proper divisors (1).

11521591 is an equidigital number, since it uses as much as digits as its factorization.

11521591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 450, while the sum is 25.

The square root of 11521591 is about 3394.3469180389. The cubic root of 11521591 is about 225.8590435940.

The spelling of 11521591 in words is "eleven million, five hundred twenty-one thousand, five hundred ninety-one".