31318840 has 144 divisors (see below), whose sum is σ = 89364600. Its totient is φ = 9821952.

The previous prime is 31318747. The next prime is 31318853. The reversal of 31318840 is 4881313.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 31318799 and 31318808.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1079946 + ... + 1079974.

Almost surely, 2^31318840 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 31318840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44682300).

31318840 is an abundant number, since it is smaller than the sum of its proper divisors (58045760).

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

31318840 is a wasteful number, since it uses less digits than its factorization.

31318840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 62 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 31318840 is about 5596.3237933486. The cubic root of 31318840 is about 315.2113807550.

The spelling of 31318840 in words is "thirty-one million, three hundred eighteen thousand, eight hundred forty".