128628381 has 24 divisors (see below), whose sum is σ = 199946880. Its totient is φ = 73339392.

The previous prime is 128628371. The next prime is 128628433. The reversal of 128628381 is 183826821.

It is not a de Polignac number, because 128628381 - 2¹⁰ = 128627357 is a prime.

It is a super-2 number, since 2×128628381² = 33090520797362322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128628361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 105085 + ... + 106301.

It is an arithmetic number, because the mean of its divisors is an integer number (8331120).

Almost surely, 2^128628381 is an apocalyptic number.

It is an amenable number.

128628381 is a deficient number, since it is larger than the sum of its proper divisors (71318499).

128628381 is a wasteful number, since it uses less digits than its factorization.

128628381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1953 (or 1946 counting only the distinct ones).

The product of its digits is 36864, while the sum is 39.

The square root of 128628381 is about 11341.4452782703. The cubic root of 128628381 is about 504.7917724675.

The spelling of 128628381 in words is "one hundred twenty-eight million, six hundred twenty-eight thousand, three hundred eighty-one".