28056761 has 4 divisors (see below), whose sum is σ = 28079232. Its totient is φ = 28034292.

The previous prime is 28056727. The next prime is 28056773. The reversal of 28056761 is 16765082.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16765082 = 2 ⋅8382541.

It is a cyclic number.

It is not a de Polignac number, because 28056761 - 2¹⁸ = 27794617 is a prime.

It is a super-2 number, since 2×28056761² = 1574363675622242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28056361) 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, 9245 + ... + 11898.

It is an arithmetic number, because the mean of its divisors is an integer number (7019808).

Almost surely, 2^28056761 is an apocalyptic number.

It is an amenable number.

28056761 is a deficient number, since it is larger than the sum of its proper divisors (22471).

28056761 is a wasteful number, since it uses less digits than its factorization.

28056761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22470.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 28056761 is about 5296.8633170963. The cubic root of 28056761 is about 303.8639489609.

The spelling of 28056761 in words is "twenty-eight million, fifty-six thousand, seven hundred sixty-one".