31310161 has 2 divisors, whose sum is σ = 31310162. Its totient is φ = 31310160.

The previous prime is 31310137. The next prime is 31310171. The reversal of 31310161 is 16101313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30195025 + 1115136 = 5495^2 + 1056^2 .

It is an emirp because it is prime and its reverse (16101313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31310161 - 2¹⁹ = 30785873 is a prime.

It is a super-3 number, since 3×31310161³ (a number of 23 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (31310171) 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, 15655080 + 15655081.

It is an arithmetic number, because the mean of its divisors is an integer number (15655081).

Almost surely, 2^31310161 is an apocalyptic number.

It is an amenable number.

31310161 is a deficient number, since it is larger than the sum of its proper divisors (1).

31310161 is an equidigital number, since it uses as much as digits as its factorization.

31310161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54, while the sum is 16.

The square root of 31310161 is about 5595.5483198700. The cubic root of 31310161 is about 315.1822611971.

Adding to 31310161 its reverse (16101313), we get a palindrome (47411474).

The spelling of 31310161 in words is "thirty-one million, three hundred ten thousand, one hundred sixty-one".