31791228281856 has 220 divisors, whose sum is σ = 95822091093168. Its totient is φ = 10498035068928.

The previous prime is 31791228281851. The next prime is 31791228281863. The reversal of 31791228281856 is 65818282219713.

31791228281856 is a `hidden beast` number, since 3 + 179 + 1 + 2 + 282 + 8 + 185 + 6 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 31791228281793 and 31791228281802.

It is not an unprimeable number, because it can be changed into a prime (31791228281851) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 7083955 + ... + 10666061.

Almost surely, 2^{31791228281856} is an apocalyptic number.

31791228281856 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31791228281856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47911045546584).

31791228281856 is an abundant number, since it is smaller than the sum of its proper divisors (64030862811312).

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

31791228281856 is a wasteful number, since it uses less digits than its factorization.

31791228281856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3582246 (or 3582219 counting only the distinct ones).

The product of its digits is 23224320, while the sum is 63.

The spelling of 31791228281856 in words is "thirty-one trillion, seven hundred ninety-one billion, two hundred twenty-eight million, two hundred eighty-one thousand, eight hundred fifty-six".