128488861 has 4 divisors (see below), whose sum is σ = 129469824. Its totient is φ = 127507900.

The previous prime is 128488847. The next prime is 128488889. The reversal of 128488861 is 168884821.

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 128488861 - 2⁷ = 128488733 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 (128488891) 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, 490285 + ... + 490546.

It is an arithmetic number, because the mean of its divisors is an integer number (32367456).

Almost surely, 2^128488861 is an apocalyptic number.

It is an amenable number.

128488861 is a deficient number, since it is larger than the sum of its proper divisors (980963).

128488861 is an equidigital number, since it uses as much as digits as its factorization.

128488861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 980962.

The product of its digits is 196608, while the sum is 46.

The square root of 128488861 is about 11335.2927178790. The cubic root of 128488861 is about 504.6091947530.

The spelling of 128488861 in words is "one hundred twenty-eight million, four hundred eighty-eight thousand, eight hundred sixty-one".