128855491 has 2 divisors, whose sum is σ = 128855492. Its totient is φ = 128855490.

The previous prime is 128855459. The next prime is 128855501. The reversal of 128855491 is 194558821.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 128855491 - 2⁵ = 128855459 is a prime.

It is not a weakly prime, because it can be changed into another prime (128855401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64427745 + 64427746.

It is an arithmetic number, because the mean of its divisors is an integer number (64427746).

Almost surely, 2^128855491 is an apocalyptic number.

128855491 is a deficient number, since it is larger than the sum of its proper divisors (1).

128855491 is an equidigital number, since it uses as much as digits as its factorization.

128855491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 115200, while the sum is 43.

The square root of 128855491 is about 11351.4532549802. The cubic root of 128855491 is about 505.0886894521.

The spelling of 128855491 in words is "one hundred twenty-eight million, eight hundred fifty-five thousand, four hundred ninety-one".