128706581 has 2 divisors, whose sum is σ = 128706582. Its totient is φ = 128706580.

The previous prime is 128706527. The next prime is 128706587. The reversal of 128706581 is 185607821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91374481 + 37332100 = 9559^2 + 6110^2 .

It is a cyclic number.

It is not a de Polignac number, because 128706581 - 2⁶ = 128706517 is a prime.

It is a super-2 number, since 2×128706581² = 33130767985419122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128706587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64353290 + 64353291.

It is an arithmetic number, because the mean of its divisors is an integer number (64353291).

Almost surely, 2^128706581 is an apocalyptic number.

It is an amenable number.

128706581 is a deficient number, since it is larger than the sum of its proper divisors (1).

128706581 is an equidigital number, since it uses as much as digits as its factorization.

128706581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26880, while the sum is 38.

The square root of 128706581 is about 11344.8922868399. The cubic root of 128706581 is about 504.8940482883.

The spelling of 128706581 in words is "one hundred twenty-eight million, seven hundred six thousand, five hundred eighty-one".