3131122121 has 4 divisors (see below), whose sum is σ = 3151065732. Its totient is φ = 3111178512.

The previous prime is 3131122097. The next prime is 3131122217. The reversal of 3131122121 is 1212211313.

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

It can be written as a sum of positive squares in 2 ways, for example, as 2204772025 + 926350096 = 46955^2 + 30436^2 .

It is a cyclic number.

It is not a de Polignac number, because 3131122121 - 2²⁶ = 3064013257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 3131122121.

It is not an unprimeable number, because it can be changed into a prime (3131122021) 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, 9971570 + ... + 9971883.

It is an arithmetic number, because the mean of its divisors is an integer number (787766433).

Almost surely, 2^3131122121 is an apocalyptic number.

It is an amenable number.

3131122121 is a deficient number, since it is larger than the sum of its proper divisors (19943611).

3131122121 is a wasteful number, since it uses less digits than its factorization.

3131122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19943610.

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

The square root of 3131122121 is about 55956.4305598561. The cubic root of 3131122121 is about 1462.9629764749.

Adding to 3131122121 its reverse (1212211313), we get a palindrome (4343333434).

The spelling of 3131122121 in words is "three billion, one hundred thirty-one million, one hundred twenty-two thousand, one hundred twenty-one".