641918 has 8 divisors (see below), whose sum is σ = 968448. Its totient is φ = 319104.

The previous prime is 641909. The next prime is 641923. The reversal of 641918 is 819146.

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

It is an Ulam number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 641918.

It is an unprimeable number.

641918 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 (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 446 + ... + 1217.

It is an arithmetic number, because the mean of its divisors is an integer number (121056).

2⁶⁴¹⁹¹⁸ is an apocalyptic number.

641918 is a deficient number, since it is larger than the sum of its proper divisors (326530).

641918 is a wasteful number, since it uses less digits than its factorization.

641918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1858.

The product of its digits is 1728, while the sum is 29.

The square root of 641918 is about 801.1978532173. The cubic root of 641918 is about 86.2633893657.

The spelling of 641918 in words is "six hundred forty-one thousand, nine hundred eighteen".