128138679 has 40 divisors (see below), whose sum is σ = 203280000. Its totient is φ = 80213328.

The previous prime is 128138677. The next prime is 128138693. The reversal of 128138679 is 976831821.

It is not a de Polignac number, because 128138679 - 2¹ = 128138677 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128138671) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 213622 + ... + 214220.

It is an arithmetic number, because the mean of its divisors is an integer number (5082000).

Almost surely, 2^128138679 is an apocalyptic number.

128138679 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

128138679 is a deficient number, since it is larger than the sum of its proper divisors (75141321).

128138679 is a wasteful number, since it uses less digits than its factorization.

128138679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 769 (or 760 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 128138679 is about 11319.8356436832. The cubic root of 128138679 is about 504.1503590503.

The spelling of 128138679 in words is "one hundred twenty-eight million, one hundred thirty-eight thousand, six hundred seventy-nine".