11515591 has 2 divisors, whose sum is σ = 11515592. Its totient is φ = 11515590.

The previous prime is 11515589. The next prime is 11515597. The reversal of 11515591 is 19551511.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11515591 - 2¹ = 11515589 is a prime.

Together with 11515589, 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 (11515597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5757795 + 5757796.

It is an arithmetic number, because the mean of its divisors is an integer number (5757796).

Almost surely, 2^11515591 is an apocalyptic number.

11515591 is a deficient number, since it is larger than the sum of its proper divisors (1).

11515591 is an equidigital number, since it uses as much as digits as its factorization.

11515591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1125, while the sum is 28.

The square root of 11515591 is about 3393.4629804965. The cubic root of 11515591 is about 225.8198305615.

The spelling of 11515591 in words is "eleven million, five hundred fifteen thousand, five hundred ninety-one".