641705520 has 160 divisors (see below), whose sum is σ = 2098151424. Its totient is φ = 161920000.

The previous prime is 641705509. The next prime is 641705521. The reversal of 641705520 is 25507146.

641705520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (641705521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 556945 + ... + 558095.

Almost surely, 2^641705520 is an apocalyptic number.

641705520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 641705520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1049075712).

641705520 is an abundant number, since it is smaller than the sum of its proper divisors (1456445904).

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

641705520 is a wasteful number, since it uses less digits than its factorization.

641705520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1291 (or 1285 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 641705520 is about 25331.9071528379. The cubic root of 641705520 is about 862.5387035772.

The spelling of 641705520 in words is "six hundred forty-one million, seven hundred five thousand, five hundred twenty".