2123121 has 48 divisors (see below), whose sum is σ = 3907008. Its totient is φ = 1008000.

The previous prime is 2123087. The next prime is 2123123. The reversal of 2123121 is 1213212.

It is not a de Polignac number, because 2123121 - 2¹⁴ = 2106737 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2123097 and 2123106.

It is not an unprimeable number, because it can be changed into a prime (2123123) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 20971 + ... + 21071.

It is an arithmetic number, because the mean of its divisors is an integer number (81396).

2^2123121 is an apocalyptic number.

2123121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2123121 is a deficient number, since it is larger than the sum of its proper divisors (1783887).

2123121 is a wasteful number, since it uses less digits than its factorization.

2123121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142 (or 135 counting only the distinct ones).

The product of its digits is 24, while the sum is 12.

The square root of 2123121 is about 1457.0933394948. The cubic root of 2123121 is about 128.5261747262.

Multiplying 2123121 by its sum of digits (12), we get a palindrome (25477452).

Adding to 2123121 its reverse (1213212), we get a palindrome (3336333).

Subtracting from 2123121 its reverse (1213212), we obtain a palindrome (909909).

It can be divided in two parts, 212 and 3121, that added together give a palindrome (3333).

The spelling of 2123121 in words is "two million, one hundred twenty-three thousand, one hundred twenty-one".