28639530 has 48 divisors (see below), whose sum is σ = 77037480. Its totient is φ = 7373184.

The previous prime is 28639529. The next prime is 28639547. The reversal of 28639530 is 3593682.

It can be written as a sum of positive squares in 4 ways, for example, as 23882769 + 4756761 = 4887^2 + 2181^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2877 + ... + 8096.

Almost surely, 2^28639530 is an apocalyptic number.

28639530 is an abundant number, since it is smaller than the sum of its proper divisors (48397950).

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

28639530 is a wasteful number, since it uses less digits than its factorization.

28639530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11015 (or 11012 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 28639530 is about 5351.5913521120. The cubic root of 28639530 is about 305.9534082593.

The spelling of 28639530 in words is "twenty-eight million, six hundred thirty-nine thousand, five hundred thirty".