31630987872 has 144 divisors (see below), whose sum is σ = 98521375680. Its totient is φ = 9546720000.

The previous prime is 31630987811. The next prime is 31630987877. The reversal of 31630987872 is 27878903613.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×31630987872² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31630987877) 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, 775279 + ... + 815057.

It is an arithmetic number, because the mean of its divisors is an integer number (684176220).

Almost surely, 2^31630987872 is an apocalyptic number.

31630987872 is a gapful number since it is divisible by the number (32) 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 31630987872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49260687840).

31630987872 is an abundant number, since it is smaller than the sum of its proper divisors (66890387808).

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

31630987872 is a wasteful number, since it uses less digits than its factorization.

31630987872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40057 (or 40046 counting only the distinct ones).

The product of its (nonzero) digits is 3048192, while the sum is 54.

The spelling of 31630987872 in words is "thirty-one billion, six hundred thirty million, nine hundred eighty-seven thousand, eight hundred seventy-two".