663666365 has 8 divisors (see below), whose sum is σ = 800800728. Its totient is φ = 527999040.

The previous prime is 663666361. The next prime is 663666407. The reversal of 663666365 is 563666366.

It can be written as a sum of positive squares in 4 ways, for example, as 62141689 + 601524676 = 7883^2 + 24526^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 663666365 - 2² = 663666361 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663666361) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 365762 + ... + 367571.

It is an arithmetic number, because the mean of its divisors is an integer number (100100091).

Almost surely, 2^663666365 is an apocalyptic number.

It is an amenable number.

663666365 is a deficient number, since it is larger than the sum of its proper divisors (137134363).

663666365 is a wasteful number, since it uses less digits than its factorization.

663666365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 733519.

The product of its digits is 2099520, while the sum is 47.

The square root of 663666365 is about 25761.7228655228. The cubic root of 663666365 is about 872.2679913926.

Subtracting from 663666365 its reverse (563666366), we obtain a palindrome (99999999).

The spelling of 663666365 in words is "six hundred sixty-three million, six hundred sixty-six thousand, three hundred sixty-five".