31313122020121 has 4 divisors (see below), whose sum is σ = 31313170617652. Its totient is φ = 31313073422592.

The previous prime is 31313122020083. The next prime is 31313122020151. The reversal of 31313122020121 is 12102022131313.

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 18443245593600 + 12869876426521 = 4294560^2 + 3587461^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31313122020121 is a prime.

It is a super-2 number, since 2×31313122020121² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31313122020092 and 31313122020101.

It is not an unprimeable number, because it can be changed into a prime (31313122020151) 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, 23319096 + ... + 24625321.

It is an arithmetic number, because the mean of its divisors is an integer number (7828292654413).

Almost surely, 2^{31313122020121} is an apocalyptic number.

It is an amenable number.

31313122020121 is a deficient number, since it is larger than the sum of its proper divisors (48597531).

31313122020121 is an equidigital number, since it uses as much as digits as its factorization.

31313122020121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48597530.

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 31313122020121 its reverse (12102022131313), we get a palindrome (43415144151434).

The spelling of 31313122020121 in words is "thirty-one trillion, three hundred thirteen billion, one hundred twenty-two million, twenty thousand, one hundred twenty-one".