611561 has 2 divisors, whose sum is σ = 611562. Its totient is φ = 611560.

The previous prime is 611557. The next prime is 611587. The reversal of 611561 is 165116.

It is a happy number.

611561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 609961 + 1600 = 781^2 + 40^2 .

It is a cyclic number.

It is not a de Polignac number, because 611561 - 2² = 611557 is a prime.

It is a Chen prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (611531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305780 + 305781.

It is an arithmetic number, because the mean of its divisors is an integer number (305781).

2⁶¹¹⁵⁶¹ is an apocalyptic number.

It is an amenable number.

611561 is a deficient number, since it is larger than the sum of its proper divisors (1).

611561 is an equidigital number, since it uses as much as digits as its factorization.

611561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 180, while the sum is 20.

The square root of 611561 is about 782.0236569312. The cubic root of 611561 is about 84.8815420267.

Adding to 611561 its reverse (165116), we get a palindrome (776677).

The spelling of 611561 in words is "six hundred eleven thousand, five hundred sixty-one".