2121723 has 6 divisors (see below), whose sum is σ = 3064724. Its totient is φ = 1414476.

The previous prime is 2121683. The next prime is 2121737. The reversal of 2121723 is 3271212.

It is not a de Polignac number, because 2121723 - 2²⁰ = 1073147 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121696 and 2121705.

It is not an unprimeable number, because it can be changed into a prime (2121793) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 117865 + ... + 117882.

2^2121723 is an apocalyptic number.

2121723 is a deficient number, since it is larger than the sum of its proper divisors (943001).

2121723 is a wasteful number, since it uses less digits than its factorization.

2121723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235753 (or 235750 counting only the distinct ones).

The product of its digits is 168, while the sum is 18.

The square root of 2121723 is about 1456.6135383141. The cubic root of 2121723 is about 128.4979585539.

Adding to 2121723 its reverse (3271212), we get a palindrome (5392935).

The spelling of 2121723 in words is "two million, one hundred twenty-one thousand, seven hundred twenty-three".