28704397 has 2 divisors, whose sum is σ = 28704398. Its totient is φ = 28704396.

The previous prime is 28704371. The next prime is 28704427. The reversal of 28704397 is 79340782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26481316 + 2223081 = 5146^2 + 1491^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28704397 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28704317) 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 as a sum of consecutive naturals, namely, 14352198 + 14352199.

It is an arithmetic number, because the mean of its divisors is an integer number (14352199).

Almost surely, 2^28704397 is an apocalyptic number.

It is an amenable number.

28704397 is a deficient number, since it is larger than the sum of its proper divisors (1).

28704397 is an equidigital number, since it uses as much as digits as its factorization.

28704397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84672, while the sum is 40.

The square root of 28704397 is about 5357.6484580457. The cubic root of 28704397 is about 306.1842234412.

The spelling of 28704397 in words is "twenty-eight million, seven hundred four thousand, three hundred ninety-seven".