28643917 has 2 divisors, whose sum is σ = 28643918. Its totient is φ = 28643916.

The previous prime is 28643897. The next prime is 28643921. The reversal of 28643917 is 71934682.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16491721 + 12152196 = 4061^2 + 3486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28643917 is a prime.

It is a super-2 number, since 2×28643917² = 1640947962205778, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28643917.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28643987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14321958 + 14321959.

It is an arithmetic number, because the mean of its divisors is an integer number (14321959).

Almost surely, 2^28643917 is an apocalyptic number.

It is an amenable number.

28643917 is a deficient number, since it is larger than the sum of its proper divisors (1).

28643917 is an equidigital number, since it uses as much as digits as its factorization.

28643917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 40.

The square root of 28643917 is about 5352.0012144991. The cubic root of 28643917 is about 305.9690294314.

The spelling of 28643917 in words is "twenty-eight million, six hundred forty-three thousand, nine hundred seventeen".