641860128 has 288 divisors, whose sum is σ = 2366582400. Its totient is φ = 160247808.

The previous prime is 641860091. The next prime is 641860129. The reversal of 641860128 is 821068146.

641860128 is a `hidden beast` number, since 6 + 41 + 8 + 601 + 2 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

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

It is a junction number, because it is equal to n+sod(n) for n = 641860092 and 641860101.

It is not an unprimeable number, because it can be changed into a prime (641860129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 497308 + ... + 498596.

It is an arithmetic number, because the mean of its divisors is an integer number (8217300).

Almost surely, 2^641860128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 641860128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1183291200).

641860128 is an abundant number, since it is smaller than the sum of its proper divisors (1724722272).

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

641860128 is a wasteful number, since it uses less digits than its factorization.

641860128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1344 (or 1333 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 641860128 is about 25334.9586145310. The cubic root of 641860128 is about 862.6079693444.

The spelling of 641860128 in words is "six hundred forty-one million, eight hundred sixty thousand, one hundred twenty-eight".