31830920 has 64 divisors (see below), whose sum is σ = 79280640. Its totient is φ = 11404800.

The previous prime is 31830907. The next prime is 31830937. The reversal of 31830920 is 2903813.

It is a self number, because there is not a number n which added to its sum of digits gives 31830920.

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 15 ways as a sum of consecutive naturals, for example, 31625 + ... + 32615.

It is an arithmetic number, because the mean of its divisors is an integer number (1238760).

Almost surely, 2^31830920 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 31830920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39640320).

31830920 is an abundant number, since it is smaller than the sum of its proper divisors (47449720).

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

31830920 is a wasteful number, since it uses less digits than its factorization.

31830920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1086 (or 1082 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 31830920 is about 5641.8897543288. The cubic root of 31830920 is about 316.9200606479.

The spelling of 31830920 in words is "thirty-one million, eight hundred thirty thousand, nine hundred twenty".