128538381 has 8 divisors (see below), whose sum is σ = 171686944. Its totient is φ = 85541040.

The previous prime is 128538367. The next prime is 128538391. The reversal of 128538381 is 183835821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 128538381 - 2¹⁵ = 128505613 is a prime.

It is a super-2 number, since 2×128538381² = 33044230780202322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128538331) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35806 + ... + 39231.

It is an arithmetic number, because the mean of its divisors is an integer number (21460868).

Almost surely, 2^128538381 is an apocalyptic number.

It is an amenable number.

128538381 is a deficient number, since it is larger than the sum of its proper divisors (43148563).

128538381 is an equidigital number, since it uses as much as digits as its factorization.

128538381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75611.

The product of its digits is 46080, while the sum is 39.

The square root of 128538381 is about 11337.4768356985. The cubic root of 128538381 is about 504.6740124024.

The spelling of 128538381 in words is "one hundred twenty-eight million, five hundred thirty-eight thousand, three hundred eighty-one".