30388640 has 24 divisors (see below), whose sum is σ = 71793540. Its totient is φ = 12155392.

The previous prime is 30388637. The next prime is 30388643. The reversal of 30388640 is 4688303.

It is an interprime number because it is at equal distance from previous prime (30388637) and next prime (30388643).

It can be written as a sum of positive squares in 2 ways, for example, as 30162064 + 226576 = 5492^2 + 476^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 30388597 and 30388606.

It is not an unprimeable number, because it can be changed into a prime (30388643) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 94805 + ... + 95124.

Almost surely, 2^30388640 is an apocalyptic number.

It is an amenable number.

30388640 is an abundant number, since it is smaller than the sum of its proper divisors (41404900).

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

30388640 is a wasteful number, since it uses less digits than its factorization.

30388640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189944 (or 189936 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 30388640 is about 5512.5892283028. The cubic root of 30388640 is about 312.0592699146.

The spelling of 30388640 in words is "thirty million, three hundred eighty-eight thousand, six hundred forty".