661446169 has 2 divisors, whose sum is σ = 661446170. Its totient is φ = 661446168.

The previous prime is 661446143. The next prime is 661446187. The reversal of 661446169 is 961644166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 606981769 + 54464400 = 24637^2 + 7380^2 .

It is a cyclic number.

It is not a de Polignac number, because 661446169 - 2⁷ = 661446041 is a prime.

It is a super-3 number, since 3×661446169³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (661446139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330723084 + 330723085.

It is an arithmetic number, because the mean of its divisors is an integer number (330723085).

Almost surely, 2^661446169 is an apocalyptic number.

It is an amenable number.

661446169 is a deficient number, since it is larger than the sum of its proper divisors (1).

661446169 is an equidigital number, since it uses as much as digits as its factorization.

661446169 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 186624, while the sum is 43.

The square root of 661446169 is about 25718.5957820407. The cubic root of 661446169 is about 871.2942242653.

The spelling of 661446169 in words is "six hundred sixty-one million, four hundred forty-six thousand, one hundred sixty-nine".