31731565140 has 216 divisors, whose sum is σ = 106033027464. Its totient is φ = 7675430400.

The previous prime is 31731565127. The next prime is 31731565171. The reversal of 31731565140 is 4156513713.

It can be written as a sum of positive squares in 4 ways, for example, as 1578631824 + 30152933316 = 39732^2 + 173646^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 31731565095 and 31731565104.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 11781634 + ... + 11784326.

Almost surely, 2^31731565140 is an apocalyptic number.

31731565140 is a gapful number since it is divisible by the number (30) 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 31731565140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53016513732).

31731565140 is an abundant number, since it is smaller than the sum of its proper divisors (74301462324).

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

31731565140 is a wasteful number, since it uses less digits than its factorization.

31731565140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3271 (or 3255 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 36.

The spelling of 31731565140 in words is "thirty-one billion, seven hundred thirty-one million, five hundred sixty-five thousand, one hundred forty".