31231211320 has 64 divisors (see below), whose sum is σ = 72085321440. Its totient is φ = 12171264000.

The previous prime is 31231211317. The next prime is 31231211321. The reversal of 31231211320 is 2311213213.

It is a super-2 number, since 2×31231211320² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31231211321) 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, 667080 + ... + 712360.

Almost surely, 2^31231211320 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 31231211320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36042660720).

31231211320 is an abundant number, since it is smaller than the sum of its proper divisors (40854110120).

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

31231211320 is a wasteful number, since it uses less digits than its factorization.

31231211320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45736 (or 45732 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 31231211320 its reverse (2311213213), we get a palindrome (33542424533).

The spelling of 31231211320 in words is "thirty-one billion, two hundred thirty-one million, two hundred eleven thousand, three hundred twenty".