31213323220 has 24 divisors (see below), whose sum is σ = 66942618624. Its totient is φ = 12219683616.

The previous prime is 31213323217. The next prime is 31213323221. The reversal of 31213323220 is 2232331213.

It is a junction number, because it is equal to n+sod(n) for n = 31213323191 and 31213323200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31213323221) 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, 16601892 + ... + 16603771.

It is an arithmetic number, because the mean of its divisors is an integer number (2789275776).

Almost surely, 2^31213323220 is an apocalyptic number.

It is an amenable number.

31213323220 is an abundant number, since it is smaller than the sum of its proper divisors (35729295404).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31213323220 is a wasteful number, since it uses less digits than its factorization.

31213323220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33205719 (or 33205717 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 22.

Adding to 31213323220 its reverse (2232331213), we get a palindrome (33445654433).

The spelling of 31213323220 in words is "thirty-one billion, two hundred thirteen million, three hundred twenty-three thousand, two hundred twenty".