2281661 has 2 divisors, whose sum is σ = 2281662. Its totient is φ = 2281660.

The previous prime is 2281651. The next prime is 2281663. The reversal of 2281661 is 1661822.

2281661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1651225 + 630436 = 1285^2 + 794^2 .

It is a cyclic number.

It is not a de Polignac number, because 2281661 - 2¹⁰ = 2280637 is a prime.

It is a Sophie Germain prime.

Together with 2281663, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is equal to p₁₆₈₂₇₂ and since 2281661 and 168272 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2281661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2281663) 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, 1140830 + 1140831.

It is an arithmetic number, because the mean of its divisors is an integer number (1140831).

2^2281661 is an apocalyptic number.

It is an amenable number.

2281661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2281661 is an equidigital number, since it uses as much as digits as its factorization.

2281661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 26.

The square root of 2281661 is about 1510.5167989797. The cubic root of 2281661 is about 131.6488408989.

The spelling of 2281661 in words is "two million, two hundred eighty-one thousand, six hundred sixty-one".