28911397 has 2 divisors, whose sum is σ = 28911398. Its totient is φ = 28911396.

The previous prime is 28911359. The next prime is 28911403. The reversal of 28911397 is 79311982.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17715681 + 11195716 = 4209^2 + 3346^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28911397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28911797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14455698 + 14455699.

It is an arithmetic number, because the mean of its divisors is an integer number (14455699).

Almost surely, 2^28911397 is an apocalyptic number.

It is an amenable number.

28911397 is a deficient number, since it is larger than the sum of its proper divisors (1).

28911397 is an equidigital number, since it uses as much as digits as its factorization.

28911397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27216, while the sum is 40.

The square root of 28911397 is about 5376.9319318734. The cubic root of 28911397 is about 306.9184708543.

The spelling of 28911397 in words is "twenty-eight million, nine hundred eleven thousand, three hundred ninety-seven".