31987872 has 240 divisors, whose sum is σ = 112698432. Its totient is φ = 8709120.

The previous prime is 31987867. The next prime is 31987883. The reversal of 31987872 is 27878913.

It is a nude number because it is divisible by every one of its digits.

Its product of digits (169344) is a multiple of the sum of its prime divisors (96).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 743883 + ... + 743925.

Almost surely, 2^31987872 is an apocalyptic number.

31987872 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 31987872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (56349216).

31987872 is an abundant number, since it is smaller than the sum of its proper divisors (80710560).

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

31987872 is a wasteful number, since it uses less digits than its factorization.

31987872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113 (or 96 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 31987872 is about 5655.7821740233. The cubic root of 31987872 is about 317.4400969923.

The spelling of 31987872 in words is "thirty-one million, nine hundred eighty-seven thousand, eight hundred seventy-two".