128795521 has 2 divisors, whose sum is σ = 128795522. Its totient is φ = 128795520.

The previous prime is 128795501. The next prime is 128795531. The reversal of 128795521 is 125597821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 89870400 + 38925121 = 9480^2 + 6239^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128795521 is a prime.

It is a super-2 number, since 2×128795521² = 33176572459322882, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (128795501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64397760 + 64397761.

It is an arithmetic number, because the mean of its divisors is an integer number (64397761).

Almost surely, 2^128795521 is an apocalyptic number.

It is an amenable number.

128795521 is a deficient number, since it is larger than the sum of its proper divisors (1).

128795521 is an equidigital number, since it uses as much as digits as its factorization.

128795521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 50400, while the sum is 40.

The square root of 128795521 is about 11348.8114355645. The cubic root of 128795521 is about 505.0103203459.

The spelling of 128795521 in words is "one hundred twenty-eight million, seven hundred ninety-five thousand, five hundred twenty-one".