28328549 has 4 divisors (see below), whose sum is σ = 28343820. Its totient is φ = 28313280.

The previous prime is 28328543. The next prime is 28328551. The reversal of 28328549 is 94582382.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14303524 + 14025025 = 3782^2 + 3745^2 .

It is a cyclic number.

It is not a de Polignac number, because 28328549 - 2²⁴ = 11551333 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28328543) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4394 + ... + 8715.

It is an arithmetic number, because the mean of its divisors is an integer number (7085955).

Almost surely, 2^28328549 is an apocalyptic number.

It is an amenable number.

28328549 is a deficient number, since it is larger than the sum of its proper divisors (15271).

28328549 is a wasteful number, since it uses less digits than its factorization.

28328549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15270.

The product of its digits is 138240, while the sum is 41.

The square root of 28328549 is about 5322.4570453880. The cubic root of 28328549 is about 304.8419821077.

The spelling of 28328549 in words is "twenty-eight million, three hundred twenty-eight thousand, five hundred forty-nine".