31404384 has 144 divisors (see below), whose sum is σ = 101896704. Its totient is φ = 9081600.

The previous prime is 31404383. The next prime is 31404403. The reversal of 31404384 is 48340413.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31404383) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 72649 + ... + 73079.

It is an arithmetic number, because the mean of its divisors is an integer number (707616).

Almost surely, 2^31404384 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 31404384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50948352).

31404384 is an abundant number, since it is smaller than the sum of its proper divisors (70492320).

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

31404384 is a wasteful number, since it uses less digits than its factorization.

31404384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 481 (or 470 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 31404384 is about 5603.9614559702. The cubic root of 31404384 is about 315.4981083753.

Adding to 31404384 its reverse (48340413), we get a palindrome (79744797).

The spelling of 31404384 in words is "thirty-one million, four hundred four thousand, three hundred eighty-four".