28756641 has 4 divisors (see below), whose sum is σ = 38342192. Its totient is φ = 19171092.

The previous prime is 28756631. The next prime is 28756657. The reversal of 28756641 is 14665782.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 28756641 - 2¹³ = 28748449 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28756641.

It is not an unprimeable number, because it can be changed into a prime (28756631) 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 in 3 ways as a sum of consecutive naturals, for example, 4792771 + ... + 4792776.

It is an arithmetic number, because the mean of its divisors is an integer number (9585548).

Almost surely, 2^28756641 is an apocalyptic number.

It is an amenable number.

28756641 is a deficient number, since it is larger than the sum of its proper divisors (9585551).

28756641 is an equidigital number, since it uses as much as digits as its factorization.

28756641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9585550.

The product of its digits is 80640, while the sum is 39.

The square root of 28756641 is about 5362.5218880672. The cubic root of 28756641 is about 306.3698697214.

The spelling of 28756641 in words is "twenty-eight million, seven hundred fifty-six thousand, six hundred forty-one".