31133920 has 48 divisors (see below), whose sum is σ = 75938688. Its totient is φ = 12049920.

The previous prime is 31133917. The next prime is 31133933. The reversal of 31133920 is 2933113.

It is a junction number, because it is equal to n+sod(n) for n = 31133891 and 31133900.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1822 + ... + 8098.

It is an arithmetic number, because the mean of its divisors is an integer number (1582056).

Almost surely, 2^31133920 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 31133920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37969344).

31133920 is an abundant number, since it is smaller than the sum of its proper divisors (44804768).

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

31133920 is a wasteful number, since it uses less digits than its factorization.

31133920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6323 (or 6315 counting only the distinct ones).

The product of its (nonzero) digits is 486, while the sum is 22.

The square root of 31133920 is about 5579.7777733526. Note that the first 5 decimals coincide. The cubic root of 31133920 is about 314.5897742153.

The spelling of 31133920 in words is "thirty-one million, one hundred thirty-three thousand, nine hundred twenty".