641886 has 64 divisors (see below), whose sum is σ = 1658880. Its totient is φ = 161280.

The previous prime is 641881. The next prime is 641891. The reversal of 641886 is 688146.

It is an interprime number because it is at equal distance from previous prime (641881) and next prime (641891).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641881) 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, 20691 + ... + 20721.

It is an arithmetic number, because the mean of its divisors is an integer number (25920).

2⁶⁴¹⁸⁸⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 641886, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (829440).

641886 is an abundant number, since it is smaller than the sum of its proper divisors (1016994).

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

641886 is a wasteful number, since it uses less digits than its factorization.

641886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89.

The product of its digits is 9216, while the sum is 33.

The square root of 641886 is about 801.1778828700. The cubic root of 641886 is about 86.2619559145.

The spelling of 641886 in words is "six hundred forty-one thousand, eight hundred eighty-six".