31317768 has 72 divisors (see below), whose sum is σ = 87739470. Its totient is φ = 10085760.

The previous prime is 31317751. The next prime is 31317779. The reversal of 31317768 is 86771313.

It can be written as a sum of positive squares in only one way, i.e., 30935844 + 381924 = 5562^2 + 618^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 304005 + ... + 304107.

Almost surely, 2^31317768 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 31317768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43869735).

31317768 is an abundant number, since it is smaller than the sum of its proper divisors (56421702).

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

31317768 is a wasteful number, since it uses less digits than its factorization.

31317768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259 (or 149 counting only the distinct ones).

The product of its digits is 21168, while the sum is 36.

The square root of 31317768 is about 5596.2280153689. The cubic root of 31317768 is about 315.2077842993.

It can be divided in two parts, 313 and 17768, that added together give a palindrome (18081).

The spelling of 31317768 in words is "thirty-one million, three hundred seventeen thousand, seven hundred sixty-eight".