28280691 has 16 divisors (see below), whose sum is σ = 43031200. Its totient is φ = 18343584.

The previous prime is 28280687. The next prime is 28280701. The reversal of 28280691 is 19608282.

It is not a de Polignac number, because 28280691 - 2² = 28280687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28280621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13156 + ... + 15153.

It is an arithmetic number, because the mean of its divisors is an integer number (2689450).

Almost surely, 2^28280691 is an apocalyptic number.

28280691 is a deficient number, since it is larger than the sum of its proper divisors (14750509).

28280691 is a wasteful number, since it uses less digits than its factorization.

28280691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28355 (or 28349 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 28280691 is about 5317.9592890506. The cubic root of 28280691 is about 304.6702195643.

The spelling of 28280691 in words is "twenty-eight million, two hundred eighty thousand, six hundred ninety-one".