641666800 has 30 divisors (see below), whose sum is σ = 1541605448. Its totient is φ = 256666560.

The previous prime is 641666791. The next prime is 641666801. The reversal of 641666800 is 8666146.

It is a self number, because there is not a number n which added to its sum of digits gives 641666800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641666801) 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, 801684 + ... + 802483.

Almost surely, 2^641666800 is an apocalyptic number.

It is an amenable number.

641666800 is an abundant number, since it is smaller than the sum of its proper divisors (899938648).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

641666800 is a wasteful number, since it uses less digits than its factorization.

641666800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1604185 (or 1604174 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 641666800 is about 25331.1428877577. The cubic root of 641666800 is about 862.5213549288.

The spelling of 641666800 in words is "six hundred forty-one million, six hundred sixty-six thousand, eight hundred".