31881274866 has 96 divisors (see below), whose sum is σ = 82058296320. Its totient is φ = 9087760656.

The previous prime is 31881274847. The next prime is 31881274897. The reversal of 31881274866 is 66847218813.

31881274866 is a `hidden beast` number, since 31 + 8 + 8 + 127 + 486 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1482805 + ... + 1504151.

It is an arithmetic number, because the mean of its divisors is an integer number (854773920).

Almost surely, 2^31881274866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31881274866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41029148160).

31881274866 is an abundant number, since it is smaller than the sum of its proper divisors (50177021454).

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

31881274866 is a wasteful number, since it uses less digits than its factorization.

31881274866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21810 (or 21798 counting only the distinct ones).

The product of its digits is 3096576, while the sum is 54.

The spelling of 31881274866 in words is "thirty-one billion, eight hundred eighty-one million, two hundred seventy-four thousand, eight hundred sixty-six".