31318129 has 2 divisors, whose sum is σ = 31318130. Its totient is φ = 31318128.

The previous prime is 31318127. The next prime is 31318159. The reversal of 31318129 is 92181313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23184225 + 8133904 = 4815^2 + 2852^2 .

It is a cyclic number.

It is not a de Polignac number, because 31318129 - 2¹ = 31318127 is a prime.

Together with 31318127, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 31318097 and 31318106.

It is not a weakly prime, because it can be changed into another prime (31318127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15659064 + 15659065.

It is an arithmetic number, because the mean of its divisors is an integer number (15659065).

Almost surely, 2^31318129 is an apocalyptic number.

It is an amenable number.

31318129 is a deficient number, since it is larger than the sum of its proper divisors (1).

31318129 is an equidigital number, since it uses as much as digits as its factorization.

31318129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 28.

The square root of 31318129 is about 5596.2602691440. The cubic root of 31318129 is about 315.2089954283.

The spelling of 31318129 in words is "thirty-one million, three hundred eighteen thousand, one hundred twenty-nine".