641885 has 4 divisors (see below), whose sum is σ = 770268. Its totient is φ = 513504.

The previous prime is 641881. The next prime is 641891. The reversal of 641885 is 588146.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 315844 + 326041 = 562^2 + 571^2 .

It is a cyclic number.

It is not a de Polignac number, because 641885 - 2² = 641881 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 14.

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 3 ways as a sum of consecutive naturals, for example, 64184 + ... + 64193.

It is an arithmetic number, because the mean of its divisors is an integer number (192567).

2⁶⁴¹⁸⁸⁵ is an apocalyptic number.

It is an amenable number.

641885 is a deficient number, since it is larger than the sum of its proper divisors (128383).

641885 is a wasteful number, since it uses less digits than its factorization.

641885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128382.

The product of its digits is 7680, while the sum is 32.

The square root of 641885 is about 801.1772587886. The cubic root of 641885 is about 86.2619111184.

The spelling of 641885 in words is "six hundred forty-one thousand, eight hundred eighty-five".