2013123121 has 4 divisors (see below), whose sum is σ = 2067531892. Its totient is φ = 1958714352.

The previous prime is 2013123113. The next prime is 2013123143. The reversal of 2013123121 is 1213213102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1213213102 = 2 ⋅606606551.

It can be written as a sum of positive squares in 2 ways, for example, as 1516323600 + 496799521 = 38940^2 + 22289^2 .

It is a cyclic number.

It is not a de Polignac number, because 2013123121 - 2³ = 2013123113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2013123095 and 2013123104.

It is not an unprimeable number, because it can be changed into a prime (2013123191) 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, 27204330 + ... + 27204403.

It is an arithmetic number, because the mean of its divisors is an integer number (516882973).

Almost surely, 2^2013123121 is an apocalyptic number.

It is an amenable number.

2013123121 is a deficient number, since it is larger than the sum of its proper divisors (54408771).

2013123121 is an equidigital number, since it uses as much as digits as its factorization.

2013123121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54408770.

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

The square root of 2013123121 is about 44867.8406099514. The cubic root of 2013123121 is about 1262.6707273086.

Adding to 2013123121 its reverse (1213213102), we get a palindrome (3226336223).

The spelling of 2013123121 in words is "two billion, thirteen million, one hundred twenty-three thousand, one hundred twenty-one".