31123212 has 48 divisors (see below), whose sum is σ = 74887680. Its totient is φ = 10055232.

The previous prime is 31123199. The next prime is 31123217. The reversal of 31123212 is 21232113.

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 = 31123191 and 31123200.

It is not an unprimeable number, because it can be changed into a prime (31123217) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78198 + ... + 78594.

It is an arithmetic number, because the mean of its divisors is an integer number (1560160).

Almost surely, 2^31123212 is an apocalyptic number.

It is an amenable number.

31123212 is an abundant number, since it is smaller than the sum of its proper divisors (43764468).

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

31123212 is a wasteful number, since it uses less digits than its factorization.

31123212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 590 (or 588 counting only the distinct ones).

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

The square root of 31123212 is about 5578.8181544123. The cubic root of 31123212 is about 314.5537040858.

Adding to 31123212 its reverse (21232113), we get a palindrome (52355325).

The spelling of 31123212 in words is "thirty-one million, one hundred twenty-three thousand, two hundred twelve".