28666403 has 4 divisors (see below), whose sum is σ = 30352680. Its totient is φ = 26980128.

The previous prime is 28666399. The next prime is 28666409. The reversal of 28666403 is 30466682.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30466682 = 2 ⋅15233341.

It is a cyclic number.

It is not a de Polignac number, because 28666403 - 2² = 28666399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28666409) 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, 843113 + ... + 843146.

It is an arithmetic number, because the mean of its divisors is an integer number (7588170).

Almost surely, 2^28666403 is an apocalyptic number.

28666403 is a deficient number, since it is larger than the sum of its proper divisors (1686277).

28666403 is a wasteful number, since it uses less digits than its factorization.

28666403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1686276.

The product of its (nonzero) digits is 41472, while the sum is 35.

The square root of 28666403 is about 5354.1015119252. The cubic root of 28666403 is about 306.0490722559.

The spelling of 28666403 in words is "twenty-eight million, six hundred sixty-six thousand, four hundred three".