28556761 has 4 divisors (see below), whose sum is σ = 28660132. Its totient is φ = 28453392.

The previous prime is 28556747. The next prime is 28556779. The reversal of 28556761 is 16765582.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9363600 + 19193161 = 3060^2 + 4381^2 .

It is a cyclic number.

It is not a de Polignac number, because 28556761 - 2⁵ = 28556729 is a prime.

It is a super-2 number, since 2×28556761² = 1630977197622242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28556701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51270 + ... + 51823.

It is an arithmetic number, because the mean of its divisors is an integer number (7165033).

Almost surely, 2^28556761 is an apocalyptic number.

It is an amenable number.

28556761 is a deficient number, since it is larger than the sum of its proper divisors (103371).

28556761 is a wasteful number, since it uses less digits than its factorization.

28556761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103370.

The product of its digits is 100800, while the sum is 40.

The square root of 28556761 is about 5343.8526364412. The cubic root of 28556761 is about 305.6583860523.

The spelling of 28556761 in words is "twenty-eight million, five hundred fifty-six thousand, seven hundred sixty-one".