11647991 has 2 divisors, whose sum is σ = 11647992. Its totient is φ = 11647990.

The previous prime is 11647973. The next prime is 11648003. The reversal of 11647991 is 19974611.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 11647991 - 2¹⁰ = 11646967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11647901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5823995 + 5823996.

It is an arithmetic number, because the mean of its divisors is an integer number (5823996).

Almost surely, 2^11647991 is an apocalyptic number.

11647991 is a deficient number, since it is larger than the sum of its proper divisors (1).

11647991 is an equidigital number, since it uses as much as digits as its factorization.

11647991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13608, while the sum is 38.

The square root of 11647991 is about 3412.9153227117. The cubic root of 11647991 is about 226.6819859408.

The spelling of 11647991 in words is "eleven million, six hundred forty-seven thousand, nine hundred ninety-one".