128597761 has 4 divisors (see below), whose sum is σ = 134188992. Its totient is φ = 123006532.

The previous prime is 128597759. The next prime is 128597767. The reversal of 128597761 is 167795821.

It is a happy number.

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 128597761 - 2¹ = 128597759 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128597767) 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, 2795581 + ... + 2795626.

It is an arithmetic number, because the mean of its divisors is an integer number (33547248).

Almost surely, 2^128597761 is an apocalyptic number.

It is an amenable number.

128597761 is a deficient number, since it is larger than the sum of its proper divisors (5591231).

128597761 is an equidigital number, since it uses as much as digits as its factorization.

128597761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5591230.

The product of its digits is 211680, while the sum is 46.

The square root of 128597761 is about 11340.0952817867. The cubic root of 128597761 is about 504.7517140434.

The spelling of 128597761 in words is "one hundred twenty-eight million, five hundred ninety-seven thousand, seven hundred sixty-one".