31312103220 has 144 divisors (see below), whose sum is σ = 97638428160. Its totient is φ = 8116616448.

The previous prime is 31312103201. The next prime is 31312103243. The reversal of 31312103220 is 2230121313.

31312103220 is a `hidden beast` number, since 3 + 131 + 210 + 322 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 31312103193 and 31312103202.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 12139891 + ... + 12142469.

It is an arithmetic number, because the mean of its divisors is an integer number (678044640).

Almost surely, 2^31312103220 is an apocalyptic number.

31312103220 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31312103220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48819214080).

31312103220 is an abundant number, since it is smaller than the sum of its proper divisors (66326324940).

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

31312103220 is a wasteful number, since it uses less digits than its factorization.

31312103220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4454 (or 4449 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 31312103220 its reverse (2230121313), we get a palindrome (33542224533).

The spelling of 31312103220 in words is "thirty-one billion, three hundred twelve million, one hundred three thousand, two hundred twenty".