31981360 has 40 divisors (see below), whose sum is σ = 74883600. Its totient is φ = 12701952.

The previous prime is 31981321. The next prime is 31981361. The reversal of 31981360 is 6318913.

It is a tau number, because it is divible by the number of its divisors (40).

It is a zygodrome in base 2.

It is not an unprimeable number, because it can be changed into a prime (31981361) 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 7 ways as a sum of consecutive naturals, for example, 10579 + ... + 13261.

It is an arithmetic number, because the mean of its divisors is an integer number (1872090).

Almost surely, 2^31981360 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31981360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37441800).

31981360 is an abundant number, since it is smaller than the sum of its proper divisors (42902240).

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

31981360 is a wasteful number, since it uses less digits than its factorization.

31981360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2845 (or 2839 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 31981360 is about 5655.2064506966. The cubic root of 31981360 is about 317.4185543464.

The spelling of 31981360 in words is "thirty-one million, nine hundred eighty-one thousand, three hundred sixty".