31318040 has 64 divisors (see below), whose sum is σ = 76507200. Its totient is φ = 11469312.

The previous prime is 31318037. The next prime is 31318043. The reversal of 31318040 is 4081313.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (31318037) and next prime (31318043).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31318043) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 118949 + ... + 119211.

It is an arithmetic number, because the mean of its divisors is an integer number (1195425).

Almost surely, 2^31318040 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 31318040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38253600).

31318040 is an abundant number, since it is smaller than the sum of its proper divisors (45189160).

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

31318040 is a wasteful number, since it uses less digits than its factorization.

31318040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 516 (or 512 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 31318040 is about 5596.2523173996. The cubic root of 31318040 is about 315.2086968406.

Adding to 31318040 its reverse (4081313), we get a palindrome (35399353).

The spelling of 31318040 in words is "thirty-one million, three hundred eighteen thousand, forty".