31920450 has 48 divisors (see below), whose sum is σ = 79581216. Its totient is φ = 8467200.

The previous prime is 31920439. The next prime is 31920451. The reversal of 31920450 is 5402913.

It is a self number, because there is not a number n which added to its sum of digits gives 31920450.

It is not an unprimeable number, because it can be changed into a prime (31920451) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 35709 + ... + 36591.

It is an arithmetic number, because the mean of its divisors is an integer number (1657942).

Almost surely, 2^31920450 is an apocalyptic number.

31920450 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 31920450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39790608).

31920450 is an abundant number, since it is smaller than the sum of its proper divisors (47660766).

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

31920450 is a wasteful number, since it uses less digits than its factorization.

31920450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1139 (or 1134 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 31920450 is about 5649.8185811582. The cubic root of 31920450 is about 317.2169134395.

The spelling of 31920450 in words is "thirty-one million, nine hundred twenty thousand, four hundred fifty".