128872757 has 4 divisors (see below), whose sum is σ = 138786060. Its totient is φ = 118959456.

The previous prime is 128872753. The next prime is 128872769. The reversal of 128872757 is 757278821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20421361 + 108451396 = 4519^2 + 10414^2 .

It is a cyclic number.

It is not a de Polignac number, because 128872757 - 2² = 128872753 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 (128872753) 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, 4956632 + ... + 4956657.

It is an arithmetic number, because the mean of its divisors is an integer number (34696515).

Almost surely, 2^128872757 is an apocalyptic number.

It is an amenable number.

128872757 is a deficient number, since it is larger than the sum of its proper divisors (9913303).

128872757 is an equidigital number, since it uses as much as digits as its factorization.

128872757 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9913302.

The product of its digits is 439040, while the sum is 47.

The square root of 128872757 is about 11352.2137488685. The cubic root of 128872757 is about 505.1112482420. Note that the first 3 decimals are identical.

The spelling of 128872757 in words is "one hundred twenty-eight million, eight hundred seventy-two thousand, seven hundred fifty-seven".