2123406 has 36 divisors (see below), whose sum is σ = 4831008. Its totient is φ = 673992.

The previous prime is 2123377. The next prime is 2123411. The reversal of 2123406 is 6043212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 9411 + ... + 9633.

2^2123406 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2123406, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2415504).

2123406 is an abundant number, since it is smaller than the sum of its proper divisors (2707602).

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

2123406 is a wasteful number, since it uses less digits than its factorization.

2123406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277 (or 251 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 2123406 is about 1457.1911336541. The cubic root of 2123406 is about 128.5319254302.

Adding to 2123406 its reverse (6043212), we get a palindrome (8166618).

The spelling of 2123406 in words is "two million, one hundred twenty-three thousand, four hundred six".