3611561 has 2 divisors, whose sum is σ = 3611562. Its totient is φ = 3611560.

The previous prime is 3611551. The next prime is 3611563. The reversal of 3611561 is 1651163.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3041536 + 570025 = 1744^2 + 755^2 .

It is an emirp because it is prime and its reverse (1651163) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3611561 - 2¹⁸ = 3349417 is a prime.

It is a Sophie Germain prime.

Together with 3611563, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (3611563) 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, 1805780 + 1805781.

It is an arithmetic number, because the mean of its divisors is an integer number (1805781).

Almost surely, 2^3611561 is an apocalyptic number.

It is an amenable number.

3611561 is a deficient number, since it is larger than the sum of its proper divisors (1).

3611561 is an equidigital number, since it uses as much as digits as its factorization.

3611561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 540, while the sum is 23.

The square root of 3611561 is about 1900.4107450759. The cubic root of 3611561 is about 153.4257723431.

The spelling of 3611561 in words is "three million, six hundred eleven thousand, five hundred sixty-one".