641855 has 16 divisors (see below), whose sum is σ = 822528. Its totient is φ = 480000.

The previous prime is 641843. The next prime is 641863. The reversal of 641855 is 558146.

It is a happy number.

It is not a de Polignac number, because 641855 - 2⁶ = 641791 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6305 + ... + 6405.

It is an arithmetic number, because the mean of its divisors is an integer number (51408).

2⁶⁴¹⁸⁵⁵ is an apocalyptic number.

641855 is a deficient number, since it is larger than the sum of its proper divisors (180673).

641855 is a wasteful number, since it uses less digits than its factorization.

641855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178.

The product of its digits is 4800, while the sum is 29.

The square root of 641855 is about 801.1585361213. The cubic root of 641855 is about 86.2605672133.

The spelling of 641855 in words is "six hundred forty-one thousand, eight hundred fifty-five".