28738321 has 2 divisors, whose sum is σ = 28738322. Its totient is φ = 28738320.

The previous prime is 28738301. The next prime is 28738343. The reversal of 28738321 is 12383782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17313921 + 11424400 = 4161^2 + 3380^2 .

It is a cyclic number.

It is not a de Polignac number, because 28738321 - 2⁵ = 28738289 is a prime.

It is not a weakly prime, because it can be changed into another prime (28738301) 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, 14369160 + 14369161.

It is an arithmetic number, because the mean of its divisors is an integer number (14369161).

Almost surely, 2^28738321 is an apocalyptic number.

It is an amenable number.

28738321 is a deficient number, since it is larger than the sum of its proper divisors (1).

28738321 is an equidigital number, since it uses as much as digits as its factorization.

28738321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16128, while the sum is 34.

The square root of 28738321 is about 5360.8134643914. The cubic root of 28738321 is about 306.3047961924.

The spelling of 28738321 in words is "twenty-eight million, seven hundred thirty-eight thousand, three hundred twenty-one".