128891557 has 2 divisors, whose sum is σ = 128891558. Its totient is φ = 128891556.

The previous prime is 128891551. The next prime is 128891591. The reversal of 128891557 is 755198821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 117809316 + 11082241 = 10854^2 + 3329^2 .

It is a cyclic number.

It is not a de Polignac number, because 128891557 - 2³ = 128891549 is a prime.

It is a super-2 number, since 2×128891557² = 33226066931768498, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128891551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64445778 + 64445779.

It is an arithmetic number, because the mean of its divisors is an integer number (64445779).

Almost surely, 2^128891557 is an apocalyptic number.

It is an amenable number.

128891557 is a deficient number, since it is larger than the sum of its proper divisors (1).

128891557 is an equidigital number, since it uses as much as digits as its factorization.

128891557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 201600, while the sum is 46.

The square root of 128891557 is about 11353.0417510022. The cubic root of 128891557 is about 505.1358089791.

The spelling of 128891557 in words is "one hundred twenty-eight million, eight hundred ninety-one thousand, five hundred fifty-seven".