11566549 has 2 divisors, whose sum is σ = 11566550. Its totient is φ = 11566548.

The previous prime is 11566547. The next prime is 11566601. The reversal of 11566549 is 94566511.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8820900 + 2745649 = 2970^2 + 1657^2 .

It is a cyclic number.

It is not a de Polignac number, because 11566549 - 2¹ = 11566547 is a prime.

Together with 11566547, 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 (11566543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5783274 + 5783275.

It is an arithmetic number, because the mean of its divisors is an integer number (5783275).

Almost surely, 2^11566549 is an apocalyptic number.

It is an amenable number.

11566549 is a deficient number, since it is larger than the sum of its proper divisors (1).

11566549 is an equidigital number, since it uses as much as digits as its factorization.

11566549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32400, while the sum is 37.

The square root of 11566549 is about 3400.9629518711. The cubic root of 11566549 is about 226.1524345567.

The spelling of 11566549 in words is "eleven million, five hundred sixty-six thousand, five hundred forty-nine".