641720880 has 200 divisors, whose sum is σ = 2245918752. Its totient is φ = 169814016.

The previous prime is 641720869. The next prime is 641720887. The reversal of 641720880 is 88027146.

641720880 is a `hidden beast` number, since 641 + 7 + 2 + 0 + 8 + 8 + 0 = 666.

641720880 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (641720887) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1081864 + ... + 1082456.

Almost surely, 2^641720880 is an apocalyptic number.

641720880 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 641720880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1122959376).

641720880 is an abundant number, since it is smaller than the sum of its proper divisors (1604197872).

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

641720880 is a wasteful number, since it uses less digits than its factorization.

641720880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 785 (or 770 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 641720880 is about 25332.2103259862. The cubic root of 641720880 is about 862.5455854923.

The spelling of 641720880 in words is "six hundred forty-one million, seven hundred twenty thousand, eight hundred eighty".