31221555040 has 96 divisors (see below), whose sum is σ = 79476102720. Its totient is φ = 11521972224.

The previous prime is 31221554983. The next prime is 31221555077. The reversal of 31221555040 is 4055512213.

It is a congruent number.

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, 7213357 + ... + 7217683.

It is an arithmetic number, because the mean of its divisors is an integer number (827876070).

Almost surely, 2^31221555040 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 31221555040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39738051360).

31221555040 is an abundant number, since it is smaller than the sum of its proper divisors (48254547680).

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

31221555040 is a wasteful number, since it uses less digits than its factorization.

31221555040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7824 (or 7816 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 28.

The spelling of 31221555040 in words is "thirty-one billion, two hundred twenty-one million, five hundred fifty-five thousand, forty".