961661 has 2 divisors, whose sum is σ = 961662. Its totient is φ = 961660.

The previous prime is 961657. The next prime is 961663. The reversal of 961661 is 166169.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 624100 + 337561 = 790^2 + 581^2 .

It is an emirp because it is prime and its reverse (166169) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 961661 - 2² = 961657 is a prime.

It is a Sophie Germain prime.

Together with 961663, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 961661.

It is not a weakly prime, because it can be changed into another prime (961663) 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, 480830 + 480831.

It is an arithmetic number, because the mean of its divisors is an integer number (480831).

2⁹⁶¹⁶⁶¹ is an apocalyptic number.

It is an amenable number.

961661 is a deficient number, since it is larger than the sum of its proper divisors (1).

961661 is an equidigital number, since it uses as much as digits as its factorization.

961661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944, while the sum is 29.

The square root of 961661 is about 980.6431563010. The cubic root of 961661 is about 98.7053443343.

The spelling of 961661 in words is "nine hundred sixty-one thousand, six hundred sixty-one".