31317120 has 96 divisors (see below), whose sum is σ = 108161820. Its totient is φ = 8349696.

The previous prime is 31317119. The next prime is 31317131. The reversal of 31317120 is 2171313.

It can be written as a sum of positive squares in 2 ways, for example, as 31270464 + 46656 = 5592^2 + 216^2 .

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

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 31317093 and 31317102.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3042 + ... + 8478.

Almost surely, 2^31317120 is an apocalyptic number.

31317120 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 31317120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54080910).

31317120 is an abundant number, since it is smaller than the sum of its proper divisors (76844700).

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

31317120 is a wasteful number, since it uses less digits than its factorization.

31317120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5462 (or 5447 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 18.

The square root of 31317120 is about 5596.1701189296. The cubic root of 31317120 is about 315.2056102826.

Adding to 31317120 its reverse (2171313), we get a palindrome (33488433).

The spelling of 31317120 in words is "thirty-one million, three hundred seventeen thousand, one hundred twenty".