31031040 has 72 divisors (see below), whose sum is σ = 99117648. Its totient is φ = 8273920.

The previous prime is 31031029. The next prime is 31031051. The reversal of 31031040 is 4013013.

It is an interprime number because it is at equal distance from previous prime (31031029) and next prime (31031051).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 201 + ... + 7880.

It is an arithmetic number, because the mean of its divisors is an integer number (1376634).

Almost surely, 2^31031040 is an apocalyptic number.

31031040 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 31031040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49558824).

31031040 is an abundant number, since it is smaller than the sum of its proper divisors (68086608).

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

31031040 is an equidigital number, since it uses as much as digits as its factorization.

31031040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8105 (or 8091 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 12.

The square root of 31031040 is about 5570.5511396988. The cubic root of 31031040 is about 314.2428780658.

Adding to 31031040 its reverse (4013013), we get a palindrome (35044053).

The spelling of 31031040 in words is "thirty-one million, thirty-one thousand, forty".