641004865 has 16 divisors (see below), whose sum is σ = 788928336. Its totient is φ = 499686400.

The previous prime is 641004857. The next prime is 641004901. The reversal of 641004865 is 568400146.

It can be written as a sum of positive squares in 8 ways, for example, as 18352656 + 622652209 = 4284^2 + 24953^2 .

It is not a de Polignac number, because 641004865 - 2³ = 641004857 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 641004865.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 243255 + ... + 245875.

It is an arithmetic number, because the mean of its divisors is an integer number (49308021).

Almost surely, 2^641004865 is an apocalyptic number.

It is an amenable number.

641004865 is a deficient number, since it is larger than the sum of its proper divisors (147923471).

641004865 is a wasteful number, since it uses less digits than its factorization.

641004865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3860.

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 641004865 is about 25318.0738801355. The cubic root of 641004865 is about 862.2246643369.

The spelling of 641004865 in words is "six hundred forty-one million, four thousand, eight hundred sixty-five".