31873211136 has 216 divisors, whose sum is σ = 100167618096. Its totient is φ = 9688227840.

The previous prime is 31873211119. The next prime is 31873211137. The reversal of 31873211136 is 63111237813.

31873211136 is a `hidden beast` number, since 318 + 7 + 321 + 1 + 13 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 31873211136.

It is not an unprimeable number, because it can be changed into a prime (31873211137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2479606 + ... + 2492426.

Almost surely, 2^31873211136 is an apocalyptic number.

31873211136 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 31873211136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50083809048).

31873211136 is an abundant number, since it is smaller than the sum of its proper divisors (68294406960).

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

31873211136 is a wasteful number, since it uses less digits than its factorization.

31873211136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12939 (or 12922 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

Adding to 31873211136 its reverse (63111237813), we get a palindrome (94984448949).

The spelling of 31873211136 in words is "thirty-one billion, eight hundred seventy-three million, two hundred eleven thousand, one hundred thirty-six".