28774561 has 2 divisors, whose sum is σ = 28774562. Its totient is φ = 28774560.

The previous prime is 28774513. The next prime is 28774573. The reversal of 28774561 is 16547782.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28558336 + 216225 = 5344^2 + 465^2 .

It is a cyclic number.

It is not a de Polignac number, because 28774561 - 2¹⁹ = 28250273 is a prime.

It is not a weakly prime, because it can be changed into another prime (28774511) 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, 14387280 + 14387281.

It is an arithmetic number, because the mean of its divisors is an integer number (14387281).

Almost surely, 2^28774561 is an apocalyptic number.

It is an amenable number.

28774561 is a deficient number, since it is larger than the sum of its proper divisors (1).

28774561 is an equidigital number, since it uses as much as digits as its factorization.

28774561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 94080, while the sum is 40.

The square root of 28774561 is about 5364.1924834965. The cubic root of 28774561 is about 306.4334956973.

The spelling of 28774561 in words is "twenty-eight million, seven hundred seventy-four thousand, five hundred sixty-one".