128478881 has 4 divisors (see below), whose sum is σ = 128508564. Its totient is φ = 128449200.

The previous prime is 128478863. The next prime is 128478899. The reversal of 128478881 is 188874821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 188874821 = 89 ⋅2122189.

It is an interprime number because it is at equal distance from previous prime (128478863) and next prime (128478899).

It can be written as a sum of positive squares in 2 ways, for example, as 32262400 + 96216481 = 5680^2 + 9809^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128478881 is a prime.

It is a super-2 number, since 2×128478881² = 33013645726024322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128478811) 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, 6950 + ... + 17471.

It is an arithmetic number, because the mean of its divisors is an integer number (32127141).

Almost surely, 2^128478881 is an apocalyptic number.

It is an amenable number.

128478881 is a deficient number, since it is larger than the sum of its proper divisors (29683).

128478881 is an equidigital number, since it uses as much as digits as its factorization.

128478881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29682.

The product of its digits is 229376, while the sum is 47.

The square root of 128478881 is about 11334.8524913207. The cubic root of 128478881 is about 504.5961297290.

The spelling of 128478881 in words is "one hundred twenty-eight million, four hundred seventy-eight thousand, eight hundred eighty-one".