100644 has 12 divisors (see below), whose sum is σ = 234864. Its totient is φ = 33544.

The previous prime is 100621. The next prime is 100649. The reversal of 100644 is 446001.

It is a tau number, because it is divible by the number of its divisors (12).

It is an Ulam number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 100644.

It is not an unprimeable number, because it can be changed into a prime (100649) by changing a digit.

100644 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 in 3 ways as a sum of consecutive naturals, for example, 4182 + ... + 4205.

It is an arithmetic number, because the mean of its divisors is an integer number (19572).

2¹⁰⁰⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

100644 is an abundant number, since it is smaller than the sum of its proper divisors (134220).

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

100644 is a wasteful number, since it uses less digits than its factorization.

100644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8394 (or 8392 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 100644 is about 317.2443852931. The cubic root of 100644 is about 46.5153146457.

Adding to 100644 its reverse (446001), we get a palindrome (546645).

The spelling of 100644 in words is "one hundred thousand, six hundred forty-four".