668620161 has 12 divisors (see below), whose sum is σ = 1053583440. Its totient is φ = 405224280.

The previous prime is 668620159. The next prime is 668620171. The reversal of 668620161 is 161026866.

668620161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 668620161 - 2¹ = 668620159 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (668620151) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3376771 + ... + 3376968.

It is an arithmetic number, because the mean of its divisors is an integer number (87798620).

Almost surely, 2^668620161 is an apocalyptic number.

It is an amenable number.

668620161 is a deficient number, since it is larger than the sum of its proper divisors (384963279).

668620161 is a wasteful number, since it uses less digits than its factorization.

668620161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6753756 (or 6753753 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 668620161 is about 25857.6905581299. The cubic root of 668620161 is about 874.4328999078.

The spelling of 668620161 in words is "six hundred sixty-eight million, six hundred twenty thousand, one hundred sixty-one".