28983781 has 2 divisors, whose sum is σ = 28983782. Its totient is φ = 28983780.

The previous prime is 28983767. The next prime is 28983817. The reversal of 28983781 is 18738982.

Together with next prime (28983817) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25411681 + 3572100 = 5041^2 + 1890^2 .

It is a cyclic number.

It is not a de Polignac number, because 28983781 - 2⁷ = 28983653 is a prime.

It is a super-2 number, since 2×28983781² = 1680119122111922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28983281) 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, 14491890 + 14491891.

It is an arithmetic number, because the mean of its divisors is an integer number (14491891).

Almost surely, 2^28983781 is an apocalyptic number.

It is an amenable number.

28983781 is a deficient number, since it is larger than the sum of its proper divisors (1).

28983781 is an equidigital number, since it uses as much as digits as its factorization.

28983781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 193536, while the sum is 46.

The square root of 28983781 is about 5383.6587001778. The cubic root of 28983781 is about 307.1743961329.

The spelling of 28983781 in words is "twenty-eight million, nine hundred eighty-three thousand, seven hundred eighty-one".