31821288084 has 144 divisors (see below), whose sum is σ = 90417600000. Its totient is φ = 9389157120.

The previous prime is 31821288077. The next prime is 31821288089. The reversal of 31821288084 is 48088212813.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31821288089) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 589042 + ... + 640790.

It is an arithmetic number, because the mean of its divisors is an integer number (627900000).

Almost surely, 2^31821288084 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 31821288084, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45208800000).

31821288084 is an abundant number, since it is smaller than the sum of its proper divisors (58596311916).

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

31821288084 is a wasteful number, since it uses less digits than its factorization.

31821288084 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51838 (or 51833 counting only the distinct ones).

The product of its (nonzero) digits is 196608, while the sum is 45.

The spelling of 31821288084 in words is "thirty-one billion, eight hundred twenty-one million, two hundred eighty-eight thousand, eighty-four".