641518728 has 32 divisors (see below), whose sum is σ = 1647144960. Its totient is φ = 208059840.

The previous prime is 641518723. The next prime is 641518729. The reversal of 641518728 is 827815146.

It is a self number, because there is not a number n which added to its sum of digits gives 641518728.

It is not an unprimeable number, because it can be changed into a prime (641518723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 360328 + ... + 362103.

It is an arithmetic number, because the mean of its divisors is an integer number (51473280).

Almost surely, 2^641518728 is an apocalyptic number.

It is an amenable number.

641518728 is an abundant number, since it is smaller than the sum of its proper divisors (1005626232).

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

641518728 is a wasteful number, since it uses less digits than its factorization.

641518728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 722477 (or 722473 counting only the distinct ones).

The product of its digits is 107520, while the sum is 42.

The square root of 641518728 is about 25328.2199927275. The cubic root of 641518728 is about 862.4550042479.

It can be divided in two parts, 641518 and 728, that added together give a palindrome (642246).

The spelling of 641518728 in words is "six hundred forty-one million, five hundred eighteen thousand, seven hundred twenty-eight".