2161123 has 4 divisors (see below), whose sum is σ = 2165128. Its totient is φ = 2157120.

The previous prime is 2161121. The next prime is 2161127. The reversal of 2161123 is 3211612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2161123 - 2¹ = 2161121 is a prime.

It is a super-2 number, since 2×2161123² = 9340905242258, which contains 22 as substring.

It is a Duffinian number.

2161123 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2161097 and 2161106.

It is not an unprimeable number, because it can be changed into a prime (2161121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1038 + ... + 2323.

It is an arithmetic number, because the mean of its divisors is an integer number (541282).

2^2161123 is an apocalyptic number.

2161123 is a deficient number, since it is larger than the sum of its proper divisors (4005).

2161123 is an equidigital number, since it uses as much as digits as its factorization.

2161123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4004.

The product of its digits is 72, while the sum is 16.

The square root of 2161123 is about 1470.0758483833. The cubic root of 2161123 is about 129.2884796518.

Adding to 2161123 its reverse (3211612), we get a palindrome (5372735).

The spelling of 2161123 in words is "two million, one hundred sixty-one thousand, one hundred twenty-three".