661802965309 has 2 divisors, whose sum is σ = 661802965310. Its totient is φ = 661802965308.

The previous prime is 661802965301. The next prime is 661802965319. The reversal of 661802965309 is 903569208166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 356874812100 + 304928153209 = 597390^2 + 552203^2 .

It is a cyclic number.

It is not a de Polignac number, because 661802965309 - 2³ = 661802965301 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 661802965309.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661802965301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330901482654 + 330901482655.

It is an arithmetic number, because the mean of its divisors is an integer number (330901482655).

Almost surely, 2^661802965309 is an apocalyptic number.

It is an amenable number.

661802965309 is a deficient number, since it is larger than the sum of its proper divisors (1).

661802965309 is an equidigital number, since it uses as much as digits as its factorization.

661802965309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4199040, while the sum is 55.

The spelling of 661802965309 in words is "six hundred sixty-one billion, eight hundred two million, nine hundred sixty-five thousand, three hundred nine".