31516531328 has 128 divisors (see below), whose sum is σ = 66133862400. Its totient is φ = 14944849920.

The previous prime is 31516531309. The next prime is 31516531357. The reversal of 31516531328 is 82313561513.

It is a tau number, because it is divible by the number of its divisors (128).

It is a junction number, because it is equal to n+sod(n) for n = 31516531291 and 31516531300.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36689363 + ... + 36690221.

It is an arithmetic number, because the mean of its divisors is an integer number (516670800).

Almost surely, 2^31516531328 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 31516531328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33066931200).

31516531328 is an abundant number, since it is smaller than the sum of its proper divisors (34617331072).

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

31516531328 is a wasteful number, since it uses less digits than its factorization.

31516531328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1098 (or 1086 counting only the distinct ones).

The product of its digits is 64800, while the sum is 38.

The spelling of 31516531328 in words is "thirty-one billion, five hundred sixteen million, five hundred thirty-one thousand, three hundred twenty-eight".