28639730 has 64 divisors (see below), whose sum is σ = 64012032. Its totient is φ = 9000960.

The previous prime is 28639729. The next prime is 28639757. The reversal of 28639730 is 3793682.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 48497 + ... + 49083.

It is an arithmetic number, because the mean of its divisors is an integer number (1000188).

Almost surely, 2^28639730 is an apocalyptic number.

28639730 is an abundant number, since it is smaller than the sum of its proper divisors (35372302).

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

28639730 is a wasteful number, since it uses less digits than its factorization.

28639730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659.

The product of its (nonzero) digits is 54432, while the sum is 38.

The square root of 28639730 is about 5351.6100381100. The cubic root of 28639730 is about 305.9541204514.

The spelling of 28639730 in words is "twenty-eight million, six hundred thirty-nine thousand, seven hundred thirty".