30531840 has 72 divisors (see below), whose sum is σ = 97523328. Its totient is φ = 8140800.

The previous prime is 30531829. The next prime is 30531877. The reversal of 30531840 is 4813503.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 30531840.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136 + ... + 7815.

Almost surely, 2^30531840 is an apocalyptic number.

30531840 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 30531840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48761664).

30531840 is an abundant number, since it is smaller than the sum of its proper divisors (66991488).

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

30531840 is an equidigital number, since it uses as much as digits as its factorization.

30531840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7975 (or 7961 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 30531840 is about 5525.5624148135. The cubic root of 30531840 is about 312.5486729520.

The spelling of 30531840 in words is "thirty million, five hundred thirty-one thousand, eight hundred forty".