128381938 has 8 divisors (see below), whose sum is σ = 192743388. Its totient is φ = 64134144.

The previous prime is 128381933. The next prime is 128381941. The reversal of 128381938 is 839183821.

It can be written as a sum of positive squares in 2 ways, for example, as 112084569 + 16297369 = 10587^2 + 4037^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 128381894 and 128381903.

It is not an unprimeable number, because it can be changed into a prime (128381933) 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, 25531 + ... + 30142.

Almost surely, 2^128381938 is an apocalyptic number.

128381938 is a deficient number, since it is larger than the sum of its proper divisors (64361450).

128381938 is a wasteful number, since it uses less digits than its factorization.

128381938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56828.

The product of its digits is 82944, while the sum is 43.

The square root of 128381938 is about 11330.5753605013. The cubic root of 128381938 is about 504.4691844268.

It can be divided in two parts, 128 and 381938, that multiplied together give a square (48888064 = 6992²).

The spelling of 128381938 in words is "one hundred twenty-eight million, three hundred eighty-one thousand, nine hundred thirty-eight".