28643897 has 2 divisors, whose sum is σ = 28643898. Its totient is φ = 28643896.

The previous prime is 28643873. The next prime is 28643917. The reversal of 28643897 is 79834682.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20286016 + 8357881 = 4504^2 + 2891^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28643897 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28643837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14321948 + 14321949.

It is an arithmetic number, because the mean of its divisors is an integer number (14321949).

Almost surely, 2^28643897 is an apocalyptic number.

It is an amenable number.

28643897 is a deficient number, since it is larger than the sum of its proper divisors (1).

28643897 is an equidigital number, since it uses as much as digits as its factorization.

28643897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 580608, while the sum is 47.

The square root of 28643897 is about 5351.9993460388. Note that the first 3 decimals coincide. The cubic root of 28643897 is about 305.9689582192.

The spelling of 28643897 in words is "twenty-eight million, six hundred forty-three thousand, eight hundred ninety-seven".