128029281 has 4 divisors (see below), whose sum is σ = 170705712. Its totient is φ = 85352852.

The previous prime is 128029271. The next prime is 128029289. The reversal of 128029281 is 182920821.

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, and also an emirpimes, since its reverse is a distinct semiprime: 182920821 = 3 ⋅60973607.

It is a cyclic number.

It is not a de Polignac number, because 128029281 - 2¹¹ = 128027233 is a prime.

It is a super-2 number, since 2×128029281² = 32782993586753922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (128029289) 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, 21338211 + ... + 21338216.

It is an arithmetic number, because the mean of its divisors is an integer number (42676428).

Almost surely, 2^128029281 is an apocalyptic number.

It is an amenable number.

128029281 is a deficient number, since it is larger than the sum of its proper divisors (42676431).

128029281 is an equidigital number, since it uses as much as digits as its factorization.

128029281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42676430.

The product of its (nonzero) digits is 4608, while the sum is 33.

The square root of 128029281 is about 11315.0024745910. The cubic root of 128029281 is about 504.0068459325.

The spelling of 128029281 in words is "one hundred twenty-eight million, twenty-nine thousand, two hundred eighty-one".