28321666 has 8 divisors (see below), whose sum is σ = 44718480. Its totient is φ = 13415508.

The previous prime is 28321651. The next prime is 28321679. The reversal of 28321666 is 66612382.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 372616 + ... + 372691.

It is an arithmetic number, because the mean of its divisors is an integer number (5589810).

Almost surely, 2^28321666 is an apocalyptic number.

28321666 is a deficient number, since it is larger than the sum of its proper divisors (16396814).

28321666 is a wasteful number, since it uses less digits than its factorization.

28321666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 745328.

The product of its digits is 20736, while the sum is 34.

The square root of 28321666 is about 5321.8104062433. The cubic root of 28321666 is about 304.8172909111.

The spelling of 28321666 in words is "twenty-eight million, three hundred twenty-one thousand, six hundred sixty-six".