31221023212 has 24 divisors (see below), whose sum is σ = 57567910400. Its totient is φ = 14774634576.

The previous prime is 31221023161. The next prime is 31221023213. The reversal of 31221023212 is 21232012213.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a self number, because there is not a number n which added to its sum of digits gives 31221023212.

It is not an unprimeable number, because it can be changed into a prime (31221023213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 118728 + ... + 276655.

Almost surely, 2^31221023212 is an apocalyptic number.

It is an amenable number.

31221023212 is a deficient number, since it is larger than the sum of its proper divisors (26346887188).

31221023212 is a wasteful number, since it uses less digits than its factorization.

31221023212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396445 (or 396443 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 31221023212 its reverse (21232012213), we get a palindrome (52453035425).

The spelling of 31221023212 in words is "thirty-one billion, two hundred twenty-one million, twenty-three thousand, two hundred twelve".