31987680 has 96 divisors (see below), whose sum is σ = 101896704. Its totient is φ = 8434176.

The previous prime is 31987663. The next prime is 31987699. The reversal of 31987680 is 8678913.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49117 + ... + 49763.

It is an arithmetic number, because the mean of its divisors is an integer number (1061424).

Almost surely, 2^31987680 is an apocalyptic number.

31987680 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 31987680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50948352).

31987680 is an abundant number, since it is smaller than the sum of its proper divisors (69909024).

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

31987680 is a wasteful number, since it uses less digits than its factorization.

31987680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 768 (or 760 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 42.

The square root of 31987680 is about 5655.7652002183. The cubic root of 31987680 is about 317.4394618701.

It can be divided in two parts, 3198 and 7680, that added together give a triangular number (10878 = T₁₄₇).

The spelling of 31987680 in words is "thirty-one million, nine hundred eighty-seven thousand, six hundred eighty".