28943557 has 2 divisors, whose sum is σ = 28943558. Its totient is φ = 28943556.

The previous prime is 28943543. The next prime is 28943561. The reversal of 28943557 is 75534982.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28718881 + 224676 = 5359^2 + 474^2 .

It is a cyclic number.

It is not a de Polignac number, because 28943557 - 2²³ = 20554949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28943527) 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, 14471778 + 14471779.

It is an arithmetic number, because the mean of its divisors is an integer number (14471779).

Almost surely, 2^28943557 is an apocalyptic number.

It is an amenable number.

28943557 is a deficient number, since it is larger than the sum of its proper divisors (1).

28943557 is an equidigital number, since it uses as much as digits as its factorization.

28943557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 302400, while the sum is 43.

The square root of 28943557 is about 5379.9216537046. The cubic root of 28943557 is about 307.0322303799.

The spelling of 28943557 in words is "twenty-eight million, nine hundred forty-three thousand, five hundred fifty-seven".