31042440 has 320 divisors, whose sum is σ = 124407360. Its totient is φ = 6842880.

The previous prime is 31042421. The next prime is 31042457. The reversal of 31042440 is 4424013.

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

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 79 ways as a sum of consecutive naturals, for example, 463287 + ... + 463353.

It is an arithmetic number, because the mean of its divisors is an integer number (388773).

Almost surely, 2^31042440 is an apocalyptic number.

31042440 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 31042440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62203680).

31042440 is an abundant number, since it is smaller than the sum of its proper divisors (93364920).

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

31042440 is a wasteful number, since it uses less digits than its factorization.

31042440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114 (or 101 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 31042440 is about 5571.5742838088. The cubic root of 31042440 is about 314.2813549179.

Adding to 31042440 its reverse (4424013), we get a palindrome (35466453).

The spelling of 31042440 in words is "thirty-one million, forty-two thousand, four hundred forty".