641813616 has 120 divisors (see below), whose sum is σ = 1956162000. Its totient is φ = 195664896.

The previous prime is 641813609. The next prime is 641813633. The reversal of 641813616 is 616318146.

641813616 is a `hidden beast` number, since 641 + 8 + 1 + 3 + 6 + 1 + 6 = 666.

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 75300 + ... + 83388.

It is an arithmetic number, because the mean of its divisors is an integer number (16301350).

Almost surely, 2^641813616 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 641813616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (978081000).

641813616 is an abundant number, since it is smaller than the sum of its proper divisors (1314348384).

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

641813616 is a wasteful number, since it uses less digits than its factorization.

641813616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8151 (or 8142 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 641813616 is about 25334.0406567922. The cubic root of 641813616 is about 862.5871327221.

The spelling of 641813616 in words is "six hundred forty-one million, eight hundred thirteen thousand, six hundred sixteen".