28388530 has 8 divisors (see below), whose sum is σ = 51099372. Its totient is φ = 11355408.

The previous prime is 28388513. The next prime is 28388533. The reversal of 28388530 is 3588382.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 27426169 + 962361 = 5237^2 + 981^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 28388530.

It is not an unprimeable number, because it can be changed into a prime (28388533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1419417 + ... + 1419436.

Almost surely, 2^28388530 is an apocalyptic number.

28388530 is a deficient number, since it is larger than the sum of its proper divisors (22710842).

28388530 is a wasteful number, since it uses less digits than its factorization.

28388530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2838860.

The product of its (nonzero) digits is 46080, while the sum is 37.

The square root of 28388530 is about 5328.0887755367. The cubic root of 28388530 is about 305.0569812020.

The spelling of 28388530 in words is "twenty-eight million, three hundred eighty-eight thousand, five hundred thirty".