631981333386 has 96 divisors (see below), whose sum is σ = 1514851648128. Its totient is φ = 189153532800.

The previous prime is 631981333289. The next prime is 631981333393. The reversal of 631981333386 is 683333189136.

631981333386 is a `hidden beast` number, since 63 + 198 + 13 + 3 + 3 + 386 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 53249425 + ... + 53261291.

It is an arithmetic number, because the mean of its divisors is an integer number (15779704668).

Almost surely, 2^631981333386 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 631981333386, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (757425824064).

631981333386 is an abundant number, since it is smaller than the sum of its proper divisors (882870314742).

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

631981333386 is a wasteful number, since it uses less digits than its factorization.

631981333386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18076 (or 18073 counting only the distinct ones).

The product of its digits is 5038848, while the sum is 54.

The spelling of 631981333386 in words is "six hundred thirty-one billion, nine hundred eighty-one million, three hundred thirty-three thousand, three hundred eighty-six".