31318161 has 16 divisors (see below), whose sum is σ = 48048000. Its totient is φ = 17774208.

The previous prime is 31318159. The next prime is 31318187. The reversal of 31318161 is 16181313.

It is not a de Polignac number, because 31318161 - 2¹ = 31318159 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31318361) 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 in 15 ways as a sum of consecutive naturals, for example, 1876 + ... + 8133.

It is an arithmetic number, because the mean of its divisors is an integer number (3003000).

Almost surely, 2^31318161 is an apocalyptic number.

It is an amenable number.

31318161 is a deficient number, since it is larger than the sum of its proper divisors (16729839).

31318161 is a wasteful number, since it uses less digits than its factorization.

31318161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10168.

The product of its digits is 432, while the sum is 24.

The square root of 31318161 is about 5596.2631281955. The cubic root of 31318161 is about 315.2091027856.

Adding to 31318161 its reverse (16181313), we get a palindrome (47499474).

The spelling of 31318161 in words is "thirty-one million, three hundred eighteen thousand, one hundred sixty-one".