641660 has 12 divisors (see below), whose sum is σ = 1347528. Its totient is φ = 256656.

The previous prime is 641639. The next prime is 641681. The reversal of 641660 is 66146.

It is an interprime number because it is at equal distance from previous prime (641639) and next prime (641681).

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

641660 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 3 ways as a sum of consecutive naturals, for example, 16022 + ... + 16061.

It is an arithmetic number, because the mean of its divisors is an integer number (112294).

2⁶⁴¹⁶⁶⁰ is an apocalyptic number.

It is an amenable number.

641660 is an abundant number, since it is smaller than the sum of its proper divisors (705868).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

641660 is a wasteful number, since it uses less digits than its factorization.

641660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32092 (or 32090 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 641660 is about 801.0368281172. The cubic root of 641660 is about 86.2518308090.

The spelling of 641660 in words is "six hundred forty-one thousand, six hundred sixty".