123406 has 4 divisors (see below), whose sum is σ = 185112. Its totient is φ = 61702.

The previous prime is 123401. The next prime is 123407. The reversal of 123406 is 604321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 604321 = 37 ⋅16333.

It is a self number, because there is not a number n which added to its sum of digits gives 123406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30850 + ... + 30853.

It is an arithmetic number, because the mean of its divisors is an integer number (46278).

2¹²³⁴⁰⁶ is an apocalyptic number.

123406 is a deficient number, since it is larger than the sum of its proper divisors (61706).

123406 is an equidigital number, since it uses as much as digits as its factorization.

123406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61705.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 123406 is about 351.2919014153. The cubic root of 123406 is about 49.7865568032.

Adding to 123406 its reverse (604321), we get a palindrome (727727).

It can be divided in two parts, 123 and 406, that added together give a square (529 = 23²).

The spelling of 123406 in words is "one hundred twenty-three thousand, four hundred six".