128565557 has 2 divisors, whose sum is σ = 128565558. Its totient is φ = 128565556.

The previous prime is 128565553. The next prime is 128565659. The reversal of 128565557 is 755565821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 107350321 + 21215236 = 10361^2 + 4606^2 .

It is a cyclic number.

It is not a de Polignac number, because 128565557 - 2² = 128565553 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128565553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64282778 + 64282779.

It is an arithmetic number, because the mean of its divisors is an integer number (64282779).

Almost surely, 2^128565557 is an apocalyptic number.

It is an amenable number.

128565557 is a deficient number, since it is larger than the sum of its proper divisors (1).

128565557 is an equidigital number, since it uses as much as digits as its factorization.

128565557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 420000, while the sum is 44.

The square root of 128565557 is about 11338.6752753573. The cubic root of 128565557 is about 504.7095764998.

The spelling of 128565557 in words is "one hundred twenty-eight million, five hundred sixty-five thousand, five hundred fifty-seven".