2121312113 has 4 divisors (see below), whose sum is σ = 2189741568. Its totient is φ = 2052882660.

The previous prime is 2121312107. The next prime is 2121312119. The reversal of 2121312113 is 3112131212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (2121312107) and next prime (2121312119).

It is a cyclic number.

It is not a de Polignac number, because 2121312113 - 2¹⁰ = 2121311089 is a prime.

It is a super-3 number, since 3×2121312113³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121312091 and 2121312100.

It is not an unprimeable number, because it can be changed into a prime (2121312119) 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, 34214681 + ... + 34214742.

It is an arithmetic number, because the mean of its divisors is an integer number (547435392).

Almost surely, 2^2121312113 is an apocalyptic number.

It is an amenable number.

2121312113 is a deficient number, since it is larger than the sum of its proper divisors (68429455).

2121312113 is an equidigital number, since it uses as much as digits as its factorization.

2121312113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68429454.

The product of its digits is 72, while the sum is 17.

The square root of 2121312113 is about 46057.7041655357. The cubic root of 2121312113 is about 1284.8966316544.

Adding to 2121312113 its reverse (3112131212), we get a palindrome (5233443325).

The spelling of 2121312113 in words is "two billion, one hundred twenty-one million, three hundred twelve thousand, one hundred thirteen".