801666361 has 2 divisors, whose sum is σ = 801666362. Its totient is φ = 801666360.

The previous prime is 801666289. The next prime is 801666377. The reversal of 801666361 is 163666108.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 725278761 + 76387600 = 26931^2 + 8740^2 .

It is a cyclic number.

It is not a de Polignac number, because 801666361 - 2⁹ = 801665849 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 801666361.

It is not a weakly prime, because it can be changed into another prime (804666361) 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, 400833180 + 400833181.

It is an arithmetic number, because the mean of its divisors is an integer number (400833181).

Almost surely, 2^801666361 is an apocalyptic number.

It is an amenable number.

801666361 is a deficient number, since it is larger than the sum of its proper divisors (1).

801666361 is an equidigital number, since it uses as much as digits as its factorization.

801666361 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 801666361 is about 28313.7133029209. The cubic root of 801666361 is about 928.9618666040.

The spelling of 801666361 in words is "eight hundred one million, six hundred sixty-six thousand, three hundred sixty-one".