28220573 has 4 divisors (see below), whose sum is σ = 28231200. Its totient is φ = 28209948.

The previous prime is 28220551. The next prime is 28220579. The reversal of 28220573 is 37502282.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 28220573 - 2⁸ = 28220317 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 (28220579) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2528 + ... + 7926.

It is an arithmetic number, because the mean of its divisors is an integer number (7057800).

Almost surely, 2^28220573 is an apocalyptic number.

It is an amenable number.

28220573 is a deficient number, since it is larger than the sum of its proper divisors (10627).

28220573 is an equidigital number, since it uses as much as digits as its factorization.

28220573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10626.

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 28220573 is about 5312.3039257934. The cubic root of 28220573 is about 304.4541810170.

The spelling of 28220573 in words is "twenty-eight million, two hundred twenty thousand, five hundred seventy-three".