128387254817 has 2 divisors, whose sum is σ = 128387254818. Its totient is φ = 128387254816.

The previous prime is 128387254783. The next prime is 128387254847. The reversal of 128387254817 is 718452783821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 116903131921 + 11484122896 = 341911^2 + 107164^2 .

It is a cyclic number.

It is not a de Polignac number, because 128387254817 - 2³⁴ = 111207385633 is a prime.

It is not a weakly prime, because it can be changed into another prime (128387254847) 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, 64193627408 + 64193627409.

It is an arithmetic number, because the mean of its divisors is an integer number (64193627409).

Almost surely, 2^128387254817 is an apocalyptic number.

It is an amenable number.

128387254817 is a deficient number, since it is larger than the sum of its proper divisors (1).

128387254817 is an equidigital number, since it uses as much as digits as its factorization.

128387254817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6021120, while the sum is 56.

The spelling of 128387254817 in words is "one hundred twenty-eight billion, three hundred eighty-seven million, two hundred fifty-four thousand, eight hundred seventeen".