31313122121 has 4 divisors (see below), whose sum is σ = 32961181200. Its totient is φ = 29665063044.

The previous prime is 31313122109. The next prime is 31313122133. The reversal of 31313122121 is 12122131313.

It is a happy number.

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 (31313122109) and next prime (31313122133).

It is a cyclic number.

It is not a de Polignac number, because 31313122121 - 2¹⁰ = 31313121097 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31313122093 and 31313122102.

It is not an unprimeable number, because it can be changed into a prime (31313122151) 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, 824029511 + ... + 824029548.

It is an arithmetic number, because the mean of its divisors is an integer number (8240295300).

Almost surely, 2^31313122121 is an apocalyptic number.

It is an amenable number.

31313122121 is a deficient number, since it is larger than the sum of its proper divisors (1648059079).

31313122121 is a wasteful number, since it uses less digits than its factorization.

31313122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1648059078.

The product of its digits is 216, while the sum is 20.

Adding to 31313122121 its reverse (12122131313), we get a palindrome (43435253434).

The spelling of 31313122121 in words is "thirty-one billion, three hundred thirteen million, one hundred twenty-two thousand, one hundred twenty-one".