28628667217 has 2 divisors, whose sum is σ = 28628667218. Its totient is φ = 28628667216.

The previous prime is 28628667187. The next prime is 28628667229. The reversal of 28628667217 is 71276682682.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22041559296 + 6587107921 = 148464^2 + 81161^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28628667217 is a prime.

It is not a weakly prime, because it can be changed into another prime (28628667317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14314333608 + 14314333609.

It is an arithmetic number, because the mean of its divisors is an integer number (14314333609).

Almost surely, 2^28628667217 is an apocalyptic number.

It is an amenable number.

28628667217 is a deficient number, since it is larger than the sum of its proper divisors (1).

28628667217 is an equidigital number, since it uses as much as digits as its factorization.

28628667217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5419008, while the sum is 55.

The spelling of 28628667217 in words is "twenty-eight billion, six hundred twenty-eight million, six hundred sixty-seven thousand, two hundred seventeen".