28666427 has 4 divisors (see below), whose sum is σ = 28795200. Its totient is φ = 28537656.

The previous prime is 28666409. The next prime is 28666433. The reversal of 28666427 is 72466682.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28666427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28666327) 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, 64052 + ... + 64497.

It is an arithmetic number, because the mean of its divisors is an integer number (7198800).

Almost surely, 2^28666427 is an apocalyptic number.

28666427 is a deficient number, since it is larger than the sum of its proper divisors (128773).

28666427 is a wasteful number, since it uses less digits than its factorization.

28666427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128772.

The product of its digits is 193536, while the sum is 41.

The square root of 28666427 is about 5354.1037531972. The cubic root of 28666427 is about 306.0491576657.

The spelling of 28666427 in words is "twenty-eight million, six hundred sixty-six thousand, four hundred twenty-seven".