128899971 has 32 divisors (see below), whose sum is σ = 206476800. Its totient is φ = 79198560.

The previous prime is 128899963. The next prime is 128899987. The reversal of 128899971 is 179998821.

It is not a de Polignac number, because 128899971 - 2³ = 128899963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128899931) 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 in 31 ways as a sum of consecutive naturals, for example, 15586 + ... + 22376.

It is an arithmetic number, because the mean of its divisors is an integer number (6452400).

Almost surely, 2^128899971 is an apocalyptic number.

128899971 is a deficient number, since it is larger than the sum of its proper divisors (77576829).

128899971 is a wasteful number, since it uses less digits than its factorization.

128899971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6856 (or 6850 counting only the distinct ones).

The product of its digits is 653184, while the sum is 54.

The square root of 128899971 is about 11353.4123064390. The cubic root of 128899971 is about 505.1468004418.

The spelling of 128899971 in words is "one hundred twenty-eight million, eight hundred ninety-nine thousand, nine hundred seventy-one".