30978720 has 192 divisors, whose sum is σ = 111041280. Its totient is φ = 8064000.

The previous prime is 30978719. The next prime is 30978733. The reversal of 30978720 is 2787903.

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

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 31 ways as a sum of consecutive naturals, for example, 306670 + ... + 306770.

It is an arithmetic number, because the mean of its divisors is an integer number (578340).

Almost surely, 2^30978720 is an apocalyptic number.

30978720 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 30978720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (55520640).

30978720 is an abundant number, since it is smaller than the sum of its proper divisors (80062560).

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

30978720 is a wasteful number, since it uses less digits than its factorization.

30978720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196 (or 182 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The square root of 30978720 is about 5565.8530343515. The cubic root of 30978720 is about 314.0661685916.

The spelling of 30978720 in words is "thirty million, nine hundred seventy-eight thousand, seven hundred twenty".