28161803 has 4 divisors (see below), whose sum is σ = 28271640. Its totient is φ = 28051968.

The previous prime is 28161797. The next prime is 28161827. The reversal of 28161803 is 30816182.

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

It is a cyclic number.

It is not a de Polignac number, because 28161803 - 2⁴ = 28161787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28161853) 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, 54533 + ... + 55046.

It is an arithmetic number, because the mean of its divisors is an integer number (7067910).

Almost surely, 2^28161803 is an apocalyptic number.

28161803 is a deficient number, since it is larger than the sum of its proper divisors (109837).

28161803 is a wasteful number, since it uses less digits than its factorization.

28161803 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109836.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 28161803 is about 5306.7695446477. The cubic root of 28161803 is about 304.2426898315.

Adding to 28161803 its reverse (30816182), we get a palindrome (58977985).

The spelling of 28161803 in words is "twenty-eight million, one hundred sixty-one thousand, eight hundred three".