28791428 has 6 divisors (see below), whose sum is σ = 50385006. Its totient is φ = 14395712.

The previous prime is 28791409. The next prime is 28791431. The reversal of 28791428 is 82419782.

It can be written as a sum of positive squares in only one way, i.e., 27541504 + 1249924 = 5248^2 + 1118^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3598925 + ... + 3598932.

It is an arithmetic number, because the mean of its divisors is an integer number (8397501).

Almost surely, 2^28791428 is an apocalyptic number.

It is an amenable number.

28791428 is a deficient number, since it is larger than the sum of its proper divisors (21593578).

28791428 is a wasteful number, since it uses less digits than its factorization.

28791428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7197861 (or 7197859 counting only the distinct ones).

The product of its digits is 64512, while the sum is 41.

The square root of 28791428 is about 5365.7644376174. The cubic root of 28791428 is about 306.4933588080.

The spelling of 28791428 in words is "twenty-eight million, seven hundred ninety-one thousand, four hundred twenty-eight".