128716591 has 2 divisors, whose sum is σ = 128716592. Its totient is φ = 128716590.

The previous prime is 128716559. The next prime is 128716631. The reversal of 128716591 is 195617821.

It is a happy number.

It is an a-pointer prime, because the next prime (128716631) can be obtained adding 128716591 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 128716591 - 2⁵ = 128716559 is a prime.

It is a super-2 number, since 2×128716591² = 33135921597322562, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128716391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64358295 + 64358296.

It is an arithmetic number, because the mean of its divisors is an integer number (64358296).

Almost surely, 2^128716591 is an apocalyptic number.

128716591 is a deficient number, since it is larger than the sum of its proper divisors (1).

128716591 is an equidigital number, since it uses as much as digits as its factorization.

128716591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 40.

The square root of 128716591 is about 11345.3334459592. Note that the first 3 decimals coincide. The cubic root of 128716591 is about 504.9071371254.

The spelling of 128716591 in words is "one hundred twenty-eight million, seven hundred sixteen thousand, five hundred ninety-one".