641785 has 8 divisors (see below), whose sum is σ = 786816. Its totient is φ = 502320.

The previous prime is 641761. The next prime is 641789. The reversal of 641785 is 587146.

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

It is not a de Polignac number, because 641785 - 2¹⁹ = 117497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641789) 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, 1131 + ... + 1600.

It is an arithmetic number, because the mean of its divisors is an integer number (98352).

2⁶⁴¹⁷⁸⁵ is an apocalyptic number.

It is an amenable number.

641785 is a deficient number, since it is larger than the sum of its proper divisors (145031).

641785 is a wasteful number, since it uses less digits than its factorization.

641785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2783.

The product of its digits is 6720, while the sum is 31.

The square root of 641785 is about 801.1148481959. The cubic root of 641785 is about 86.2574312718.

It can be divided in two parts, 64 and 1785, that added together give a square (1849 = 43²).

The spelling of 641785 in words is "six hundred forty-one thousand, seven hundred eighty-five".