28306973 has 4 divisors (see below), whose sum is σ = 28566780. Its totient is φ = 28047168.

The previous prime is 28306969. The next prime is 28306981. The reversal of 28306973 is 37960382.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10099684 + 18207289 = 3178^2 + 4267^2 .

It is a cyclic number.

It is not a de Polignac number, because 28306973 - 2² = 28306969 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 (28306963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129740 + ... + 129957.

It is an arithmetic number, because the mean of its divisors is an integer number (7141695).

Almost surely, 2^28306973 is an apocalyptic number.

It is an amenable number.

28306973 is a deficient number, since it is larger than the sum of its proper divisors (259807).

28306973 is a wasteful number, since it uses less digits than its factorization.

28306973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259806.

The product of its (nonzero) digits is 54432, while the sum is 38.

The square root of 28306973 is about 5320.4297758734. The cubic root of 28306973 is about 304.7645697284.

The spelling of 28306973 in words is "twenty-eight million, three hundred six thousand, nine hundred seventy-three".