128666893 has 2 divisors, whose sum is σ = 128666894. Its totient is φ = 128666892.

The previous prime is 128666869. The next prime is 128666921. The reversal of 128666893 is 398666821.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 118439689 + 10227204 = 10883^2 + 3198^2 .

It is a cyclic number.

It is not a de Polignac number, because 128666893 - 2¹⁷ = 128535821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128666093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64333446 + 64333447.

It is an arithmetic number, because the mean of its divisors is an integer number (64333447).

Almost surely, 2^128666893 is an apocalyptic number.

It is an amenable number.

128666893 is a deficient number, since it is larger than the sum of its proper divisors (1).

128666893 is an equidigital number, since it uses as much as digits as its factorization.

128666893 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 746496, while the sum is 49.

The square root of 128666893 is about 11343.1429947788. The cubic root of 128666893 is about 504.8421465263.

The spelling of 128666893 in words is "one hundred twenty-eight million, six hundred sixty-six thousand, eight hundred ninety-three".