128266693 has 2 divisors, whose sum is σ = 128266694. Its totient is φ = 128266692.

The previous prime is 128266673. The next prime is 128266709. The reversal of 128266693 is 396662821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 112402404 + 15864289 = 10602^2 + 3983^2 .

It is an emirp because it is prime and its reverse (396662821) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128266693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128266603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64133346 + 64133347.

It is an arithmetic number, because the mean of its divisors is an integer number (64133347).

Almost surely, 2^128266693 is an apocalyptic number.

It is an amenable number.

128266693 is a deficient number, since it is larger than the sum of its proper divisors (1).

128266693 is an equidigital number, since it uses as much as digits as its factorization.

128266693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 186624, while the sum is 43.

The square root of 128266693 is about 11325.4886428798. The cubic root of 128266693 is about 504.3181897804.

The spelling of 128266693 in words is "one hundred twenty-eight million, two hundred sixty-six thousand, six hundred ninety-three".