28790081 has 2 divisors, whose sum is σ = 28790082. Its totient is φ = 28790080.

The previous prime is 28790071. The next prime is 28790087. The reversal of 28790081 is 18009782.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27615025 + 1175056 = 5255^2 + 1084^2 .

It is a cyclic number.

It is not a de Polignac number, because 28790081 - 2⁶ = 28790017 is a prime.

It is a super-2 number, since 2×28790081² = 1657737527973122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (28790087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14395040 + 14395041.

It is an arithmetic number, because the mean of its divisors is an integer number (14395041).

Almost surely, 2^28790081 is an apocalyptic number.

It is an amenable number.

28790081 is a deficient number, since it is larger than the sum of its proper divisors (1).

28790081 is an equidigital number, since it uses as much as digits as its factorization.

28790081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 28790081 is about 5365.6389181532. The cubic root of 28790081 is about 306.4885789942.

The spelling of 28790081 in words is "twenty-eight million, seven hundred ninety thousand, eighty-one".