31384451538 has 128 divisors (see below), whose sum is σ = 77999708160. Its totient is φ = 9271765440.

The previous prime is 31384451479. The next prime is 31384451569. The reversal of 31384451538 is 83515448313.

It is a happy number.

31384451538 is a `hidden beast` number, since 31 + 3 + 84 + 4 + 5 + 1 + 538 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 31384451493 and 31384451502.

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 63 ways as a sum of consecutive naturals, for example, 21020320 + ... + 21021812.

It is an arithmetic number, because the mean of its divisors is an integer number (609372720).

Almost surely, 2^31384451538 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31384451538, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38999854080).

31384451538 is an abundant number, since it is smaller than the sum of its proper divisors (46615256622).

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

31384451538 is a wasteful number, since it uses less digits than its factorization.

31384451538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2381 (or 2375 counting only the distinct ones).

The product of its digits is 691200, while the sum is 45.

The spelling of 31384451538 in words is "thirty-one billion, three hundred eighty-four million, four hundred fifty-one thousand, five hundred thirty-eight".