128957719 has 4 divisors (see below), whose sum is σ = 140681160. Its totient is φ = 117234280.

The previous prime is 128957687. The next prime is 128957749. The reversal of 128957719 is 917759821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 917759821 = 11 ⋅83432711.

It is a cyclic number.

It is not a de Polignac number, because 128957719 - 2⁵ = 128957687 is a prime.

It is a super-2 number, since 2×128957719² = 33260186579365922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128957749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5861704 + ... + 5861725.

It is an arithmetic number, because the mean of its divisors is an integer number (35170290).

Almost surely, 2^128957719 is an apocalyptic number.

128957719 is a deficient number, since it is larger than the sum of its proper divisors (11723441).

128957719 is a wasteful number, since it uses less digits than its factorization.

128957719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11723440.

The product of its digits is 317520, while the sum is 49.

The square root of 128957719 is about 11355.9552218208. The cubic root of 128957719 is about 505.2222254969. Note that the first 5 decimals are identical.

The spelling of 128957719 in words is "one hundred twenty-eight million, nine hundred fifty-seven thousand, seven hundred nineteen".