11661571 has 2 divisors, whose sum is σ = 11661572. Its totient is φ = 11661570.

The previous prime is 11661569. The next prime is 11661607. The reversal of 11661571 is 17516611.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11661571 - 2¹ = 11661569 is a prime.

Together with 11661569, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (11661271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5830785 + 5830786.

It is an arithmetic number, because the mean of its divisors is an integer number (5830786).

Almost surely, 2^11661571 is an apocalyptic number.

11661571 is a deficient number, since it is larger than the sum of its proper divisors (1).

11661571 is an equidigital number, since it uses as much as digits as its factorization.

11661571 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1260, while the sum is 28.

The square root of 11661571 is about 3414.9042446312. The cubic root of 11661571 is about 226.7700453561.

The spelling of 11661571 in words is "eleven million, six hundred sixty-one thousand, five hundred seventy-one".