31131213120 has 504 divisors, whose sum is σ = 126705664800. Its totient is φ = 6993229824.

The previous prime is 31131213109. The next prime is 31131213149. The reversal of 31131213120 is 2131213113.

It is a tau number, because it is divible by the number of its divisors (504).

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 = 31131213093 and 31131213102.

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 71 ways as a sum of consecutive naturals, for example, 8324211 + ... + 8327949.

Almost surely, 2^31131213120 is an apocalyptic number.

31131213120 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 31131213120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63352832400).

31131213120 is an abundant number, since it is smaller than the sum of its proper divisors (95574451680).

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

31131213120 is a wasteful number, since it uses less digits than its factorization.

31131213120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3835 (or 3815 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 31131213120 its reverse (2131213113), we get a palindrome (33262426233).

The spelling of 31131213120 in words is "thirty-one billion, one hundred thirty-one million, two hundred thirteen thousand, one hundred twenty".