31012120320 has 144 divisors (see below), whose sum is σ = 99116666880. Its totient is φ = 8263913472.

The previous prime is 31012120297. The next prime is 31012120331. The reversal of 31012120320 is 2302121013.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 31012120320.

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 15 ways as a sum of consecutive naturals, for example, 8595957 + ... + 8599563.

Almost surely, 2^31012120320 is an apocalyptic number.

31012120320 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 31012120320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49558333440).

31012120320 is an abundant number, since it is smaller than the sum of its proper divisors (68104546560).

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

31012120320 is a wasteful number, since it uses less digits than its factorization.

31012120320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5870 (or 5856 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 31012120320 its reverse (2302121013), we get a palindrome (33314241333).

The spelling of 31012120320 in words is "thirty-one billion, twelve million, one hundred twenty thousand, three hundred twenty".