31987134720 has 432 divisors, whose sum is σ = 117853090992. Its totient is φ = 7982284800.

The previous prime is 31987134689. The next prime is 31987134727. The reversal of 31987134720 is 2743178913.

It can be written as a sum of positive squares in 8 ways, for example, as 462422016 + 31524712704 = 21504^2 + 177552^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (31987134727) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 45630370 + ... + 45631070.

It is an arithmetic number, because the mean of its divisors is an integer number (272808081).

Almost surely, 2^31987134720 is an apocalyptic number.

31987134720 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 31987134720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (58926545496).

31987134720 is an abundant number, since it is smaller than the sum of its proper divisors (85865956272).

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

31987134720 is a wasteful number, since it uses less digits than its factorization.

31987134720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 978 (or 961 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 45.

The spelling of 31987134720 in words is "thirty-one billion, nine hundred eighty-seven million, one hundred thirty-four thousand, seven hundred twenty".