31121212113 has 24 divisors (see below), whose sum is σ = 45553271400. Its totient is φ = 20471769600.

The previous prime is 31121212033. The next prime is 31121212123.

31121212113 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 26015109264 + 5106102849 = 161292^2 + 71457^2 .

It is not a de Polignac number, because 31121212113 - 2¹³ = 31121203921 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31121212123) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 207913 + ... + 324761.

It is an arithmetic number, because the mean of its divisors is an integer number (1898052975).

Almost surely, 2^31121212113 is an apocalyptic number.

It is an amenable number.

31121212113 is a deficient number, since it is larger than the sum of its proper divisors (14432059287).

31121212113 is a wasteful number, since it uses less digits than its factorization.

31121212113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117249 (or 117246 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

The spelling of 31121212113 in words is "thirty-one billion, one hundred twenty-one million, two hundred twelve thousand, one hundred thirteen".