31321313320 has 64 divisors (see below), whose sum is σ = 76957776000. Its totient is φ = 11377985280.

The previous prime is 31321313279. The next prime is 31321313329. The reversal of 31321313320 is 2331312313.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 31321313291 and 31321313300.

It is not an unprimeable number, because it can be changed into a prime (31321313329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 402981 + ... + 474379.

It is an arithmetic number, because the mean of its divisors is an integer number (1202465250).

Almost surely, 2^31321313320 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31321313320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38478888000).

31321313320 is an abundant number, since it is smaller than the sum of its proper divisors (45636462680).

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

31321313320 is a wasteful number, since it uses less digits than its factorization.

31321313320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72418 (or 72414 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 22.

Adding to 31321313320 its reverse (2331312313), we get a palindrome (33652625633).

The spelling of 31321313320 in words is "thirty-one billion, three hundred twenty-one million, three hundred thirteen thousand, three hundred twenty".