128139886 has 16 divisors (see below), whose sum is σ = 222138720. Its totient is φ = 54299520.

The previous prime is 128139827. The next prime is 128139899. The reversal of 128139886 is 688931821.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50175 + ... + 52666.

It is an arithmetic number, because the mean of its divisors is an integer number (13883670).

Almost surely, 2^128139886 is an apocalyptic number.

128139886 is a deficient number, since it is larger than the sum of its proper divisors (93998834).

128139886 is a wasteful number, since it uses less digits than its factorization.

128139886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102939.

The product of its digits is 165888, while the sum is 46.

The square root of 128139886 is about 11319.8889570525. Note that the first 3 decimals coincide. The cubic root of 128139886 is about 504.1519419904.

The spelling of 128139886 in words is "one hundred twenty-eight million, one hundred thirty-nine thousand, eight hundred eighty-six".