31321212 has 96 divisors (see below), whose sum is σ = 82978560. Its totient is φ = 9131520.

The previous prime is 31321163. The next prime is 31321219. The reversal of 31321212 is 21212313.

It is a super-2 number, since 2×31321212² = 1962036642297888, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 31321191 and 31321200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31321219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 377323 + ... + 377405.

It is an arithmetic number, because the mean of its divisors is an integer number (864360).

Almost surely, 2^31321212 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31321212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41489280).

31321212 is an abundant number, since it is smaller than the sum of its proper divisors (51657348).

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

31321212 is a wasteful number, since it uses less digits than its factorization.

31321212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203 (or 201 counting only the distinct ones).

The product of its digits is 72, while the sum is 15.

The square root of 31321212 is about 5596.5357141718. The cubic root of 31321212 is about 315.2193382923.

Adding to 31321212 its reverse (21212313), we get a palindrome (52533525).

The spelling of 31321212 in words is "thirty-one million, three hundred twenty-one thousand, two hundred twelve".