31221212212 has 12 divisors (see below), whose sum is σ = 54849718980. Its totient is φ = 15549863936.

The previous prime is 31221212203. The next prime is 31221212261. The reversal of 31221212212 is 21221212213.

It can be written as a sum of positive squares in 2 ways, for example, as 20769421456 + 10451790756 = 144116^2 + 102234^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 31221212212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15184387 + ... + 15186442.

It is an arithmetic number, because the mean of its divisors is an integer number (4570809915).

Almost surely, 2^31221212212 is an apocalyptic number.

It is an amenable number.

31221212212 is a deficient number, since it is larger than the sum of its proper divisors (23628506768).

31221212212 is a wasteful number, since it uses less digits than its factorization.

31221212212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30371090 (or 30371088 counting only the distinct ones).

The product of its digits is 192, while the sum is 19.

Adding to 31221212212 its reverse (21221212213), we get a palindrome (52442424425).

Subtracting from 31221212212 its reverse (21221212213), we obtain a palindrome (9999999999).

The spelling of 31221212212 in words is "thirty-one billion, two hundred twenty-one million, two hundred twelve thousand, two hundred twelve".