31133216 has 36 divisors (see below), whose sum is σ = 62491086. Its totient is φ = 15267840.

The previous prime is 31133213. The next prime is 31133231. The reversal of 31133216 is 61233113.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 29116816 + 2016400 = 5396^2 + 1420^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31133213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 161216 + ... + 161408.

Almost surely, 2^31133216 is an apocalyptic number.

It is an amenable number.

31133216 is an abundant number, since it is smaller than the sum of its proper divisors (31357870).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31133216 is an equidigital number, since it uses as much as digits as its factorization.

31133216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345 (or 266 counting only the distinct ones).

The product of its digits is 324, while the sum is 20.

The square root of 31133216 is about 5579.7146880463. The cubic root of 31133216 is about 314.5874030301.

Adding to 31133216 its reverse (61233113), we get a palindrome (92366329).

The spelling of 31133216 in words is "thirty-one million, one hundred thirty-three thousand, two hundred sixteen".