641644 has 12 divisors (see below), whose sum is σ = 1147104. Its totient is φ = 313904.

The previous prime is 641639. The next prime is 641681. The reversal of 641644 is 446146.

641644 = T₃₂₁ + T₃₂₂ + ... + T₃₃₂.

641644 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1519 + ... + 1894.

It is an arithmetic number, because the mean of its divisors is an integer number (95592).

2⁶⁴¹⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

641644 is a deficient number, since it is larger than the sum of its proper divisors (505460).

641644 is a wasteful number, since it uses less digits than its factorization.

641644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3464 (or 3462 counting only the distinct ones).

The product of its digits is 2304, while the sum is 25.

The square root of 641644 is about 801.0268409985. The cubic root of 641644 is about 86.2511138973.

The spelling of 641644 in words is "six hundred forty-one thousand, six hundred forty-four".