128938757 has 4 divisors (see below), whose sum is σ = 130492320. Its totient is φ = 127385196.

The previous prime is 128938751. The next prime is 128938781. The reversal of 128938757 is 757839821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 128938757 - 2⁴ = 128938741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128938751) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 776657 + ... + 776822.

It is an arithmetic number, because the mean of its divisors is an integer number (32623080).

Almost surely, 2^128938757 is an apocalyptic number.

It is an amenable number.

128938757 is a deficient number, since it is larger than the sum of its proper divisors (1553563).

128938757 is an equidigital number, since it uses as much as digits as its factorization.

128938757 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1553562.

The product of its digits is 846720, while the sum is 50.

The square root of 128938757 is about 11355.1202987903. The cubic root of 128938757 is about 505.1974615833.

The spelling of 128938757 in words is "one hundred twenty-eight million, nine hundred thirty-eight thousand, seven hundred fifty-seven".