31513553640 has 192 divisors, whose sum is σ = 103490946000. Its totient is φ = 8316112896.

The previous prime is 31513553551. The next prime is 31513553671. The reversal of 31513553640 is 4635531513.

31513553640 is a `hidden beast` number, since 3 + 1 + 5 + 1 + 3 + 5 + 5 + 3 + 640 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 1335610116 + 30177943524 = 36546^2 + 173718^2 .

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 = 31513553595 and 31513553604.

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 47 ways as a sum of consecutive naturals, for example, 16788382 + ... + 16790258.

Almost surely, 2^31513553640 is an apocalyptic number.

31513553640 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 31513553640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51745473000).

31513553640 is an abundant number, since it is smaller than the sum of its proper divisors (71977392360).

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

31513553640 is a wasteful number, since it uses less digits than its factorization.

31513553640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2356 (or 2349 counting only the distinct ones).

The product of its (nonzero) digits is 81000, while the sum is 36.

The spelling of 31513553640 in words is "thirty-one billion, five hundred thirteen million, five hundred fifty-three thousand, six hundred forty".