28289730 has 64 divisors (see below), whose sum is σ = 78382080. Its totient is φ = 6400704.

The previous prime is 28289693. The next prime is 28289749. The reversal of 28289730 is 3798282.

28289730 = T₉₁₆ + T₉₁₇ + ... + T₉₇₈.

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, 21841 + ... + 23099.

It is an arithmetic number, because the mean of its divisors is an integer number (1224720).

Almost surely, 2^28289730 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28289730, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39191040).

28289730 is an abundant number, since it is smaller than the sum of its proper divisors (50092350).

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

28289730 is a wasteful number, since it uses less digits than its factorization.

28289730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1383.

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 28289730 is about 5318.8090772277. The cubic root of 28289730 is about 304.7026754046.

The spelling of 28289730 in words is "twenty-eight million, two hundred eighty-nine thousand, seven hundred thirty".