641701720 has 128 divisors (see below), whose sum is σ = 1683892800. Its totient is φ = 219310080.

The previous prime is 641701681. The next prime is 641701721. The reversal of 641701720 is 27107146.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641701721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 904726 + ... + 905434.

Almost surely, 2^641701720 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 641701720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (841946400).

641701720 is an abundant number, since it is smaller than the sum of its proper divisors (1042191080).

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

641701720 is a wasteful number, since it uses less digits than its factorization.

641701720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 770 (or 744 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 641701720 is about 25331.8321485044. The cubic root of 641701720 is about 862.5370010031.

Adding to 641701720 its reverse (27107146), we get a palindrome (668808866).

The spelling of 641701720 in words is "six hundred forty-one million, seven hundred one thousand, seven hundred twenty".