28639578 has 32 divisors (see below), whose sum is σ = 62741952. Its totient is φ = 8643200.

The previous prime is 28639571. The next prime is 28639601. The reversal of 28639578 is 87593682.

It is not an unprimeable number, because it can be changed into a prime (28639571) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 18598 + ... + 20078.

It is an arithmetic number, because the mean of its divisors is an integer number (1960686).

Almost surely, 2^28639578 is an apocalyptic number.

28639578 is an abundant number, since it is smaller than the sum of its proper divisors (34102374).

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

28639578 is a wasteful number, since it uses less digits than its factorization.

28639578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1790.

The product of its digits is 725760, while the sum is 48.

The square root of 28639578 is about 5351.5958367575. The cubic root of 28639578 is about 305.9535791857.

The spelling of 28639578 in words is "twenty-eight million, six hundred thirty-nine thousand, five hundred seventy-eight".