31581284436 has 144 divisors (see below), whose sum is σ = 89157088384. Its totient is φ = 9362366208.

The previous prime is 31581284407. The next prime is 31581284453. The reversal of 31581284436 is 63448218513.

31581284436 is a `hidden beast` number, since 3 + 1 + 581 + 28 + 4 + 43 + 6 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 31581284391 and 31581284400.

It is a congruent number.

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, 1774695 + ... + 1792401.

Almost surely, 2^31581284436 is an apocalyptic number.

31581284436 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 31581284436, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44578544192).

31581284436 is an abundant number, since it is smaller than the sum of its proper divisors (57575803948).

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

31581284436 is a wasteful number, since it uses less digits than its factorization.

31581284436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17870 (or 17865 counting only the distinct ones).

The product of its digits is 552960, while the sum is 45.

The spelling of 31581284436 in words is "thirty-one billion, five hundred eighty-one million, two hundred eighty-four thousand, four hundred thirty-six".