31040040 has 64 divisors (see below), whose sum is σ = 95650560. Its totient is φ = 8052480.

The previous prime is 31040029. The next prime is 31040047. The reversal of 31040040 is 4004013.

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

It is a junction number, because it is equal to n+sod(n) for n = 31039998 and 31040025.

It is not an unprimeable number, because it can be changed into a prime (31040047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 945 + ... + 7935.

It is an arithmetic number, because the mean of its divisors is an integer number (1494540).

Almost surely, 2^31040040 is an apocalyptic number.

31040040 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 31040040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47825280).

31040040 is an abundant number, since it is smaller than the sum of its proper divisors (64610520).

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

31040040 is a wasteful number, since it uses less digits than its factorization.

31040040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7042 (or 7038 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 31040040 is about 5571.3589006633. The cubic root of 31040040 is about 314.2732553109.

Adding to 31040040 its reverse (4004013), we get a palindrome (35044053).

The spelling of 31040040 in words is "thirty-one million, forty thousand, forty".