28692221 has 8 divisors (see below), whose sum is σ = 29122560. Its totient is φ = 28265328.

The previous prime is 28692217. The next prime is 28692227. The reversal of 28692221 is 12229682.

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 28692221 - 2² = 28692217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28692227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19220 + ... + 20658.

It is an arithmetic number, because the mean of its divisors is an integer number (3640320).

Almost surely, 2^28692221 is an apocalyptic number.

It is an amenable number.

28692221 is a deficient number, since it is larger than the sum of its proper divisors (430339).

28692221 is a wasteful number, since it uses less digits than its factorization.

28692221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1723.

The product of its digits is 6912, while the sum is 32.

The square root of 28692221 is about 5356.5120180954. The cubic root of 28692221 is about 306.1409243099.

The spelling of 28692221 in words is "twenty-eight million, six hundred ninety-two thousand, two hundred twenty-one".