641020728 has 64 divisors (see below), whose sum is σ = 1667128320. Its totient is φ = 205171200.

The previous prime is 641020711. The next prime is 641020729. The reversal of 641020728 is 827020146.

It is a junction number, because it is equal to n+sod(n) for n = 641020695 and 641020704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641020729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 94176 + ... + 100752.

It is an arithmetic number, because the mean of its divisors is an integer number (26048880).

Almost surely, 2^641020728 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 641020728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (833564160).

641020728 is an abundant number, since it is smaller than the sum of its proper divisors (1026107592).

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

641020728 is a wasteful number, since it uses less digits than its factorization.

641020728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6748 (or 6744 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 641020728 is about 25318.3871524234. The cubic root of 641020728 is about 862.2317767931.

The spelling of 641020728 in words is "six hundred forty-one million, twenty thousand, seven hundred twenty-eight".