31221321212 has 6 divisors (see below), whose sum is σ = 54637312128. Its totient is φ = 15610660604.

The previous prime is 31221321203. The next prime is 31221321221. The reversal of 31221321212 is 21212312213.

It is an interprime number because it is at equal distance from previous prime (31221321203) and next prime (31221321221).

It is a super-2 number, since 2×31221321212² (a number of 22 digits) contains 22 as substring.

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, 3902665148 + ... + 3902665155.

It is an arithmetic number, because the mean of its divisors is an integer number (9106218688).

Almost surely, 2^31221321212 is an apocalyptic number.

It is an amenable number.

31221321212 is a deficient number, since it is larger than the sum of its proper divisors (23415990916).

31221321212 is a wasteful number, since it uses less digits than its factorization.

31221321212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7805330307 (or 7805330305 counting only the distinct ones).

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

Adding to 31221321212 its reverse (21212312213), we get a palindrome (52433633425).

The spelling of 31221321212 in words is "thirty-one billion, two hundred twenty-one million, three hundred twenty-one thousand, two hundred twelve".