28077221 has 8 divisors (see below), whose sum is σ = 28584480. Its totient is φ = 27572688.

The previous prime is 28077197. The next prime is 28077229. The reversal of 28077221 is 12277082.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28077221 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 (28077229) 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 7 ways as a sum of consecutive naturals, for example, 41135 + ... + 41811.

It is an arithmetic number, because the mean of its divisors is an integer number (3573060).

Almost surely, 2^28077221 is an apocalyptic number.

It is an amenable number.

28077221 is a deficient number, since it is larger than the sum of its proper divisors (507259).

28077221 is an equidigital number, since it uses as much as digits as its factorization.

28077221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1363.

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 28077221 is about 5298.7942968189. The cubic root of 28077221 is about 303.9377938566.

The spelling of 28077221 in words is "twenty-eight million, seventy-seven thousand, two hundred twenty-one".