11661491 has 2 divisors, whose sum is σ = 11661492. Its totient is φ = 11661490.

The previous prime is 11661467. The next prime is 11661523. The reversal of 11661491 is 19416611.

11661491 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 (19416611) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11661491 - 2¹⁸ = 11399347 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (11661691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5830745 + 5830746.

It is an arithmetic number, because the mean of its divisors is an integer number (5830746).

Almost surely, 2^11661491 is an apocalyptic number.

11661491 is a deficient number, since it is larger than the sum of its proper divisors (1).

11661491 is an equidigital number, since it uses as much as digits as its factorization.

11661491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 29.

The square root of 11661491 is about 3414.8925312519. The cubic root of 11661491 is about 226.7695267969.

The spelling of 11661491 in words is "eleven million, six hundred sixty-one thousand, four hundred ninety-one".