28387081 has 2 divisors, whose sum is σ = 28387082. Its totient is φ = 28387080.

The previous prime is 28387067. The next prime is 28387087. The reversal of 28387081 is 18078382.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28302400 + 84681 = 5320^2 + 291^2 .

It is a cyclic number.

It is not a de Polignac number, because 28387081 - 2⁹ = 28386569 is a prime.

It is a super-2 number, since 2×28387081² = 1611652735401122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28387081.

It is not a weakly prime, because it can be changed into another prime (28387087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14193540 + 14193541.

It is an arithmetic number, because the mean of its divisors is an integer number (14193541).

Almost surely, 2^28387081 is an apocalyptic number.

It is an amenable number.

28387081 is a deficient number, since it is larger than the sum of its proper divisors (1).

28387081 is an equidigital number, since it uses as much as digits as its factorization.

28387081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21504, while the sum is 37.

The square root of 28387081 is about 5327.9527963374. The cubic root of 28387081 is about 305.0517909005.

The spelling of 28387081 in words is "twenty-eight million, three hundred eighty-seven thousand, eighty-one".