28406665 has 8 divisors (see below), whose sum is σ = 38957760. Its totient is φ = 19478832.

The previous prime is 28406647. The next prime is 28406699. The reversal of 28406665 is 56660482.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28406665 - 2¹⁷ = 28275593 is a prime.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 405775 + ... + 405844.

It is an arithmetic number, because the mean of its divisors is an integer number (4869720).

Almost surely, 2^28406665 is an apocalyptic number.

It is an amenable number.

28406665 is a deficient number, since it is larger than the sum of its proper divisors (10551095).

28406665 is an equidigital number, since it uses as much as digits as its factorization.

28406665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 811631.

The product of its (nonzero) digits is 69120, while the sum is 37.

The square root of 28406665 is about 5329.7903335872. The cubic root of 28406665 is about 305.1219256326.

The spelling of 28406665 in words is "twenty-eight million, four hundred six thousand, six hundred sixty-five".