31116121 has 4 divisors (see below), whose sum is σ = 31401700. Its totient is φ = 30830544.

The previous prime is 31116109. The next prime is 31116139. The reversal of 31116121 is 12161113.

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 18156121 + 12960000 = 4261^2 + 3600^2 .

It is a cyclic number.

It is not a de Polignac number, because 31116121 - 2¹¹ = 31114073 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31116095 and 31116104.

It is not an unprimeable number, because it can be changed into a prime (31116191) 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, 142626 + ... + 142843.

It is an arithmetic number, because the mean of its divisors is an integer number (7850425).

Almost surely, 2^31116121 is an apocalyptic number.

It is an amenable number.

31116121 is a deficient number, since it is larger than the sum of its proper divisors (285579).

31116121 is a wasteful number, since it uses less digits than its factorization.

31116121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285578.

The product of its digits is 36, while the sum is 16.

The square root of 31116121 is about 5578.1825893386. The cubic root of 31116121 is about 314.5298133455.

Adding to 31116121 its reverse (12161113), we get a palindrome (43277234).

The spelling of 31116121 in words is "thirty-one million, one hundred sixteen thousand, one hundred twenty-one".