668420641 has 8 divisors (see below), whose sum is σ = 797122944. Its totient is φ = 548021760.

The previous prime is 668420639. The next prime is 668420657. The reversal of 668420641 is 146024866.

668420641 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 668420641 - 2¹ = 668420639 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 668420641.

It is not an unprimeable number, because it can be changed into a prime (668420611) 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, 2075680 + ... + 2076001.

It is an arithmetic number, because the mean of its divisors is an integer number (99640368).

Almost surely, 2^668420641 is an apocalyptic number.

It is an amenable number.

668420641 is a deficient number, since it is larger than the sum of its proper divisors (128702303).

668420641 is a wasteful number, since it uses less digits than its factorization.

668420641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4151711.

The product of its (nonzero) digits is 55296, while the sum is 37.

The square root of 668420641 is about 25853.8322304451. The cubic root of 668420641 is about 874.3459126968.

The spelling of 668420641 in words is "six hundred sixty-eight million, four hundred twenty thousand, six hundred forty-one".