2001121123 has 4 divisors (see below), whose sum is σ = 2023605720. Its totient is φ = 1978636528.

The previous prime is 2001121117. The next prime is 2001121139. The reversal of 2001121123 is 3211211002.

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 2001121123 - 2⁵ = 2001121091 is a prime.

It is a super-2 number, since 2×2001121123² = 8008971497833562258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2001121193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11242165 + ... + 11242342.

It is an arithmetic number, because the mean of its divisors is an integer number (505901430).

Almost surely, 2^2001121123 is an apocalyptic number.

2001121123 is a deficient number, since it is larger than the sum of its proper divisors (22484597).

2001121123 is an equidigital number, since it uses as much as digits as its factorization.

2001121123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22484596.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 2001121123 is about 44733.8923300891. The cubic root of 2001121123 is about 1260.1564269971.

Adding to 2001121123 its reverse (3211211002), we get a palindrome (5212332125).

The spelling of 2001121123 in words is "two billion, one million, one hundred twenty-one thousand, one hundred twenty-three".