123644 has 6 divisors (see below), whose sum is σ = 216384. Its totient is φ = 61820.

The previous prime is 123637. The next prime is 123653. The reversal of 123644 is 446321.

It is a happy 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 123644.

It is an unprimeable 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 as a sum of consecutive naturals, namely, 15452 + ... + 15459.

It is an arithmetic number, because the mean of its divisors is an integer number (36064).

2¹²³⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

123644 is a deficient number, since it is larger than the sum of its proper divisors (92740).

123644 is a wasteful number, since it uses less digits than its factorization.

123644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30915 (or 30913 counting only the distinct ones).

The product of its digits is 576, while the sum is 20.

The square root of 123644 is about 351.6304878704. The cubic root of 123644 is about 49.8185422584.

Adding to 123644 its reverse (446321), we get a palindrome (569965).

It can be divided in two parts, 123 and 644, that added together give a palindrome (767).

The spelling of 123644 in words is "one hundred twenty-three thousand, six hundred forty-four".