641765 has 8 divisors (see below), whose sum is σ = 791160. Its totient is φ = 499392.

The previous prime is 641761. The next prime is 641789. The reversal of 641765 is 567146.

It can be written as a sum of positive squares in 4 ways, for example, as 36481 + 605284 = 191^2 + 778^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 641765 - 2² = 641761 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1550 + ... + 1919.

It is an arithmetic number, because the mean of its divisors is an integer number (98895).

2⁶⁴¹⁷⁶⁵ is an apocalyptic number.

It is an amenable number.

641765 is a deficient number, since it is larger than the sum of its proper divisors (149395).

641765 is a wasteful number, since it uses less digits than its factorization.

641765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3511.

The product of its digits is 5040, while the sum is 29.

The square root of 641765 is about 801.1023654939. The cubic root of 641765 is about 86.2565352466.

The spelling of 641765 in words is "six hundred forty-one thousand, seven hundred sixty-five".