28161011 has 4 divisors (see below), whose sum is σ = 28238112. Its totient is φ = 28083912.

The previous prime is 28160999. The next prime is 28161017. The reversal of 28161011 is 11016182.

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 28161011 - 2²² = 23966707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28161017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38000 + ... + 38733.

It is an arithmetic number, because the mean of its divisors is an integer number (7059528).

Almost surely, 2^28161011 is an apocalyptic number.

28161011 is a deficient number, since it is larger than the sum of its proper divisors (77101).

28161011 is an equidigital number, since it uses as much as digits as its factorization.

28161011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77100.

The product of its (nonzero) digits is 96, while the sum is 20.

The square root of 28161011 is about 5306.6949224541. The cubic root of 28161011 is about 304.2398377122.

Adding to 28161011 its reverse (11016182), we get a palindrome (39177193).

The spelling of 28161011 in words is "twenty-eight million, one hundred sixty-one thousand, eleven".