31212213 has 8 divisors (see below), whose sum is σ = 41683776. Its totient is φ = 20774400.

The previous prime is 31212197. The next prime is 31212227. The reversal of 31212213 is 31221213.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31212213 - 2⁴ = 31212197 is a prime.

It is a super-3 number, since 3×31212213³ (a number of 23 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31212192 and 31212201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31212253) 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 7 ways as a sum of consecutive naturals, for example, 6193 + ... + 10038.

It is an arithmetic number, because the mean of its divisors is an integer number (5210472).

Almost surely, 2^31212213 is an apocalyptic number.

It is an amenable number.

31212213 is a deficient number, since it is larger than the sum of its proper divisors (10471563).

31212213 is a wasteful number, since it uses less digits than its factorization.

31212213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16875.

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

The square root of 31212213 is about 5586.7891494131. The cubic root of 31212213 is about 314.8532549035.

Adding to 31212213 its reverse (31221213), we get a palindrome (62433426).

The spelling of 31212213 in words is "thirty-one million, two hundred twelve thousand, two hundred thirteen".