28679561 has 4 divisors (see below), whose sum is σ = 30366612. Its totient is φ = 26992512.

The previous prime is 28679549. The next prime is 28679587. The reversal of 28679561 is 16597682.

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 19193161 + 9486400 = 4381^2 + 3080^2 .

It is a cyclic number.

It is not a de Polignac number, because 28679561 - 2¹⁰ = 28678537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28679461) 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, 843500 + ... + 843533.

It is an arithmetic number, because the mean of its divisors is an integer number (7591653).

Almost surely, 2^28679561 is an apocalyptic number.

It is an amenable number.

28679561 is a deficient number, since it is larger than the sum of its proper divisors (1687051).

28679561 is a wasteful number, since it uses less digits than its factorization.

28679561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1687050.

The product of its digits is 181440, while the sum is 44.

The square root of 28679561 is about 5355.3301485529. The cubic root of 28679561 is about 306.0958910320.

The spelling of 28679561 in words is "twenty-eight million, six hundred seventy-nine thousand, five hundred sixty-one".