31728708912 has 80 divisors (see below), whose sum is σ = 86480159360. Its totient is φ = 9996327936.

The previous prime is 31728708899. The next prime is 31728708941. The reversal of 31728708912 is 21980782713.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 354723 + ... + 435069.

It is an arithmetic number, because the mean of its divisors is an integer number (1081001992).

Almost surely, 2^31728708912 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 31728708912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43240079680).

31728708912 is an abundant number, since it is smaller than the sum of its proper divisors (54751450448).

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

31728708912 is a wasteful number, since it uses less digits than its factorization.

31728708912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80810 (or 80804 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 48.

The spelling of 31728708912 in words is "thirty-one billion, seven hundred twenty-eight million, seven hundred eight thousand, nine hundred twelve".