28306223 has 4 divisors (see below), whose sum is σ = 30879528. Its totient is φ = 25732920.

The previous prime is 28306217. The next prime is 28306247. The reversal of 28306223 is 32260382.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28306223 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28306192 and 28306201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28306273) 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, 1286636 + ... + 1286657.

It is an arithmetic number, because the mean of its divisors is an integer number (7719882).

Almost surely, 2^28306223 is an apocalyptic number.

28306223 is a deficient number, since it is larger than the sum of its proper divisors (2573305).

28306223 is a wasteful number, since it uses less digits than its factorization.

28306223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2573304.

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 28306223 is about 5320.3592923787. The cubic root of 28306223 is about 304.7618781014.

The spelling of 28306223 in words is "twenty-eight million, three hundred six thousand, two hundred twenty-three".