641786368 has 40 divisors (see below), whose sum is σ = 1303404300. Its totient is φ = 315617280.

The previous prime is 641786339. The next prime is 641786371. The reversal of 641786368 is 863687146.

It can be written as a sum of positive squares in 2 ways, for example, as 641507584 + 278784 = 25328^2 + 528^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20958 + ... + 41506.

Almost surely, 2^641786368 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 641786368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (651702150).

641786368 is an abundant number, since it is smaller than the sum of its proper divisors (661617932).

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

641786368 is an equidigital number, since it uses as much as digits as its factorization.

641786368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20628 (or 20612 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 49.

The square root of 641786368 is about 25333.5028766256. The cubic root of 641786368 is about 862.5749255921.

The spelling of 641786368 in words is "six hundred forty-one million, seven hundred eighty-six thousand, three hundred sixty-eight".