641895 has 8 divisors (see below), whose sum is σ = 1027056. Its totient is φ = 342336.

The previous prime is 641891. The next prime is 641897. The reversal of 641895 is 598146.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 641895 - 2² = 641891 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

641895 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21382 + ... + 21411.

It is an arithmetic number, because the mean of its divisors is an integer number (128382).

2⁶⁴¹⁸⁹⁵ is an apocalyptic number.

641895 is a deficient number, since it is larger than the sum of its proper divisors (385161).

641895 is a wasteful number, since it uses less digits than its factorization.

641895 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42801.

The product of its digits is 8640, while the sum is 33.

The square root of 641895 is about 801.1834995805. The cubic root of 641895 is about 86.2623590775.

The spelling of 641895 in words is "six hundred forty-one thousand, eight hundred ninety-five".