128121739 has 8 divisors (see below), whose sum is σ = 132930000. Its totient is φ = 123339552.

The previous prime is 128121733. The next prime is 128121767. The reversal of 128121739 is 937121821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 128121739 - 2⁷ = 128121611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128121733) 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 7 ways as a sum of consecutive naturals, for example, 3792 + ... + 16450.

It is an arithmetic number, because the mean of its divisors is an integer number (16616250).

Almost surely, 2^128121739 is an apocalyptic number.

128121739 is a deficient number, since it is larger than the sum of its proper divisors (4808261).

128121739 is a wasteful number, since it uses less digits than its factorization.

128121739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13037.

The product of its digits is 6048, while the sum is 34.

The square root of 128121739 is about 11319.0873748726. The cubic root of 128121739 is about 504.1281417580.

The spelling of 128121739 in words is "one hundred twenty-eight million, one hundred twenty-one thousand, seven hundred thirty-nine".