28780441 has 4 divisors (see below), whose sum is σ = 29772900. Its totient is φ = 27787984.

The previous prime is 28780417. The next prime is 28780463. The reversal of 28780441 is 14408782.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 14408782 = 2 ⋅7204391.

It can be written as a sum of positive squares in 2 ways, for example, as 19324816 + 9455625 = 4396^2 + 3075^2 .

It is a cyclic number.

It is not a de Polignac number, because 28780441 - 2⁷ = 28780313 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28780397 and 28780406.

It is not an unprimeable number, because it can be changed into a prime (28786441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 496186 + ... + 496243.

It is an arithmetic number, because the mean of its divisors is an integer number (7443225).

Almost surely, 2^28780441 is an apocalyptic number.

It is an amenable number.

28780441 is a deficient number, since it is larger than the sum of its proper divisors (992459).

28780441 is an equidigital number, since it uses as much as digits as its factorization.

28780441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 992458.

The product of its (nonzero) digits is 14336, while the sum is 34.

The square root of 28780441 is about 5364.7405342663. The cubic root of 28780441 is about 306.4543672145.

The spelling of 28780441 in words is "twenty-eight million, seven hundred eighty thousand, four hundred forty-one".