28299223 has 4 divisors (see below), whose sum is σ = 29529648. Its totient is φ = 27068800.

The previous prime is 28299221. The next prime is 28299233. The reversal of 28299223 is 32299282.

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

It is a cyclic number.

It is not a de Polignac number, because 28299223 - 2¹ = 28299221 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 (28299221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 615178 + ... + 615223.

It is an arithmetic number, because the mean of its divisors is an integer number (7382412).

Almost surely, 2^28299223 is an apocalyptic number.

28299223 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

28299223 is the 2844-th centered heptagonal number.

28299223 is a deficient number, since it is larger than the sum of its proper divisors (1230425).

28299223 is a wasteful number, since it uses less digits than its factorization.

28299223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1230424.

The product of its digits is 31104, while the sum is 37.

The square root of 28299223 is about 5319.7014013946. The cubic root of 28299223 is about 304.7367539555.

The spelling of 28299223 in words is "twenty-eight million, two hundred ninety-nine thousand, two hundred twenty-three".