128759491 has 4 divisors (see below), whose sum is σ = 147153712. Its totient is φ = 110365272.

The previous prime is 128759489. The next prime is 128759503. The reversal of 128759491 is 194957821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 194957821 = 23 ⋅8476427.

It is a cyclic number.

It is not a de Polignac number, because 128759491 - 2¹ = 128759489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128759401) 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, 9197100 + ... + 9197113.

It is an arithmetic number, because the mean of its divisors is an integer number (36788428).

Almost surely, 2^128759491 is an apocalyptic number.

128759491 is a deficient number, since it is larger than the sum of its proper divisors (18394221).

128759491 is an equidigital number, since it uses as much as digits as its factorization.

128759491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18394220.

The product of its digits is 181440, while the sum is 46.

The square root of 128759491 is about 11347.2239336324. The cubic root of 128759491 is about 504.9632244566.

It can be divided in two parts, 12875 and 9491, that added together give a triangular number (22366 = T₂₁₁).

The spelling of 128759491 in words is "one hundred twenty-eight million, seven hundred fifty-nine thousand, four hundred ninety-one".