31221312212 has 6 divisors (see below), whose sum is σ = 54637296378. Its totient is φ = 15610656104.

The previous prime is 31221312181. The next prime is 31221312263. The reversal of 31221312212 is 21221312213.

It can be written as a sum of positive squares in only one way, i.e., 17380730896 + 13840581316 = 131836^2 + 117646^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3902664023 + ... + 3902664030.

It is an arithmetic number, because the mean of its divisors is an integer number (9106216063).

Almost surely, 2^31221312212 is an apocalyptic number.

It is an amenable number.

31221312212 is a deficient number, since it is larger than the sum of its proper divisors (23415984166).

31221312212 is a wasteful number, since it uses less digits than its factorization.

31221312212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7805328057 (or 7805328055 counting only the distinct ones).

The product of its digits is 288, while the sum is 20.

Adding to 31221312212 its reverse (21221312213), we get a palindrome (52442624425).

Subtracting from 31221312212 its reverse (21221312213), we obtain a palindrome (9999999999).

The spelling of 31221312212 in words is "thirty-one billion, two hundred twenty-one million, three hundred twelve thousand, two hundred twelve".