30388428 has 144 divisors (see below), whose sum is σ = 94348800. Its totient is φ = 8227296.

The previous prime is 30388411. The next prime is 30388439. The reversal of 30388428 is 82488303.

It is a happy number.

It is a super-2 number, since 2×30388428² = 1846913112622368, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 30388392 and 30388401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 283951 + ... + 284057.

It is an arithmetic number, because the mean of its divisors is an integer number (655200).

Almost surely, 2^30388428 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 30388428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47174400).

30388428 is an abundant number, since it is smaller than the sum of its proper divisors (63960372).

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

30388428 is a wasteful number, since it uses less digits than its factorization.

30388428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161 (or 142 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The square root of 30388428 is about 5512.5699995556. The cubic root of 30388428 is about 312.0585442408.

The spelling of 30388428 in words is "thirty million, three hundred eighty-eight thousand, four hundred twenty-eight".