31135121 has 2 divisors, whose sum is σ = 31135122. Its totient is φ = 31135120.

The previous prime is 31135079. The next prime is 31135147. The reversal of 31135121 is 12153113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22515025 + 8620096 = 4745^2 + 2936^2 .

It is a cyclic number.

It is not a de Polignac number, because 31135121 - 2⁶ = 31135057 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31135121.

It is not a weakly prime, because it can be changed into another prime (31135151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15567560 + 15567561.

It is an arithmetic number, because the mean of its divisors is an integer number (15567561).

Almost surely, 2^31135121 is an apocalyptic number.

It is an amenable number.

31135121 is a deficient number, since it is larger than the sum of its proper divisors (1).

31135121 is an equidigital number, since it uses as much as digits as its factorization.

31135121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90, while the sum is 17.

The square root of 31135121 is about 5579.8853930883. The cubic root of 31135121 is about 314.5938192939.

Adding to 31135121 its reverse (12153113), we get a palindrome (43288234).

The spelling of 31135121 in words is "thirty-one million, one hundred thirty-five thousand, one hundred twenty-one".