641865 has 16 divisors (see below), whose sum is σ = 1173888. Its totient is φ = 293376.

The previous prime is 641863. The next prime is 641867. The reversal of 641865 is 568146.

641865 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 (641863) and next prime (641867).

It is not a de Polignac number, because 641865 - 2¹ = 641863 is a prime.

It is a Curzon number.

641865 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (641863) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2952 + ... + 3161.

It is an arithmetic number, because the mean of its divisors is an integer number (73368).

2⁶⁴¹⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

641865 is a deficient number, since it is larger than the sum of its proper divisors (532023).

641865 is a wasteful number, since it uses less digits than its factorization.

641865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6128.

The product of its digits is 5760, while the sum is 30.

The square root of 641865 is about 801.1647770590. The cubic root of 641865 is about 86.2610151863.

The spelling of 641865 in words is "six hundred forty-one thousand, eight hundred sixty-five".