28321973 has 2 divisors, whose sum is σ = 28321974. Its totient is φ = 28321972.

The previous prime is 28321967. The next prime is 28321991. The reversal of 28321973 is 37912382.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25421764 + 2900209 = 5042^2 + 1703^2 .

It is a cyclic number.

It is not a de Polignac number, because 28321973 - 2⁴ = 28321957 is a prime.

It is a super-2 number, since 2×28321973² = 1604268309225458, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28321903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14160986 + 14160987.

It is an arithmetic number, because the mean of its divisors is an integer number (14160987).

Almost surely, 2^28321973 is an apocalyptic number.

It is an amenable number.

28321973 is a deficient number, since it is larger than the sum of its proper divisors (1).

28321973 is an equidigital number, since it uses as much as digits as its factorization.

28321973 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 35.

The square root of 28321973 is about 5321.8392497331. The cubic root of 28321973 is about 304.8183922890.

The spelling of 28321973 in words is "twenty-eight million, three hundred twenty-one thousand, nine hundred seventy-three".