31983840 has 288 divisors, whose sum is σ = 132088320. Its totient is φ = 6884352.

The previous prime is 31983827. The next prime is 31983863. The reversal of 31983840 is 4838913.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×31983840² = 2045932042291200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 31983795 and 31983804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 191437 + ... + 191603.

It is an arithmetic number, because the mean of its divisors is an integer number (458640).

Almost surely, 2^31983840 is an apocalyptic number.

31983840 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 31983840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66044160).

31983840 is an abundant number, since it is smaller than the sum of its proper divisors (100104480).

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

31983840 is a wasteful number, since it uses less digits than its factorization.

31983840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214 (or 203 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 31983840 is about 5655.4257134189. The cubic root of 31983840 is about 317.4267588929.

It can be divided in two parts, 31983 and 840, that added together give a palindrome (32823).

The spelling of 31983840 in words is "thirty-one million, nine hundred eighty-three thousand, eight hundred forty".