31120121 has 2 divisors, whose sum is σ = 31120122. Its totient is φ = 31120120.

The previous prime is 31120109. The next prime is 31120153. The reversal of 31120121 is 12102113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19044496 + 12075625 = 4364^2 + 3475^2 .

It is a cyclic number.

It is not a de Polignac number, because 31120121 - 2¹⁸ = 30857977 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31120181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15560060 + 15560061.

It is an arithmetic number, because the mean of its divisors is an integer number (15560061).

Almost surely, 2^31120121 is an apocalyptic number.

It is an amenable number.

31120121 is a deficient number, since it is larger than the sum of its proper divisors (1).

31120121 is an equidigital number, since it uses as much as digits as its factorization.

31120121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 31120121 is about 5578.5411175324. The cubic root of 31120121 is about 314.5432904468.

Adding to 31120121 its reverse (12102113), we get a palindrome (43222234).

The spelling of 31120121 in words is "thirty-one million, one hundred twenty thousand, one hundred twenty-one".