28305081 has 12 divisors (see below), whose sum is σ = 46725952. Its totient is φ = 16174296.

The previous prime is 28305071. The next prime is 28305097. The reversal of 28305081 is 18050382.

It is a happy number.

It is not a de Polignac number, because 28305081 - 2⁹ = 28304569 is a prime.

It is a super-2 number, since 2×28305081² = 1602355220833122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28305001) 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 11 ways as a sum of consecutive naturals, for example, 224581 + ... + 224706.

Almost surely, 2^28305081 is an apocalyptic number.

28305081 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

28305081 is a deficient number, since it is larger than the sum of its proper divisors (18420871).

28305081 is a wasteful number, since it uses less digits than its factorization.

28305081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449300 (or 449297 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 28305081 is about 5320.2519677173. The cubic root of 28305081 is about 304.7577795592.

The spelling of 28305081 in words is "twenty-eight million, three hundred five thousand, eighty-one".