663668361 has 6 divisors (see below), whose sum is σ = 958632090. Its totient is φ = 442445568.

The previous prime is 663668351. The next prime is 663668363. The reversal of 663668361 is 163866366.

It is a happy number.

663668361 is a `hidden beast` number, since 6 + 636 + 6 + 8 + 3 + 6 + 1 = 666.

663668361 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 526427136 + 137241225 = 22944^2 + 11715^2 .

It is not a de Polignac number, because 663668361 - 2¹⁵ = 663635593 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (663668363) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36870456 + ... + 36870473.

It is an arithmetic number, because the mean of its divisors is an integer number (159772015).

Almost surely, 2^663668361 is an apocalyptic number.

It is an amenable number.

663668361 is a deficient number, since it is larger than the sum of its proper divisors (294963729).

663668361 is a wasteful number, since it uses less digits than its factorization.

663668361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73740935 (or 73740932 counting only the distinct ones).

The product of its digits is 559872, while the sum is 45.

The square root of 663668361 is about 25761.7616051387. The cubic root of 663668361 is about 872.2688658507.

The spelling of 663668361 in words is "six hundred sixty-three million, six hundred sixty-eight thousand, three hundred sixty-one".