641656 has 8 divisors (see below), whose sum is σ = 1203120. Its totient is φ = 320824.

The previous prime is 641639. The next prime is 641681. The reversal of 641656 is 656146.

641656 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

641656 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40096 + ... + 40111.

It is an arithmetic number, because the mean of its divisors is an integer number (150390).

2⁶⁴¹⁶⁵⁶ is an apocalyptic number.

It is an amenable number.

641656 is a deficient number, since it is larger than the sum of its proper divisors (561464).

641656 is a wasteful number, since it uses less digits than its factorization.

641656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80213 (or 80209 counting only the distinct ones).

The product of its digits is 4320, while the sum is 28.

The square root of 641656 is about 801.0343313492. The cubic root of 641656 is about 86.2516515822.

The spelling of 641656 in words is "six hundred forty-one thousand, six hundred fifty-six".