641628 has 48 divisors (see below), whose sum is σ = 1795360. Its totient is φ = 196992.

The previous prime is 641623. The next prime is 641633. The reversal of 641628 is 826146.

641628 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (641623) and next prime (641633).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641623) by changing a digit.

641628 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1176 + ... + 1632.

2⁶⁴¹⁶²⁸ 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 641628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (897680).

641628 is an abundant number, since it is smaller than the sum of its proper divisors (1153732).

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

641628 is a wasteful number, since it uses less digits than its factorization.

641628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 483 (or 475 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 641628 is about 801.0168537553. The cubic root of 641628 is about 86.2503969736.

Subtracting from 641628 its sum of digits (27), we obtain a square (641601 = 801²).

The spelling of 641628 in words is "six hundred forty-one thousand, six hundred twenty-eight".