128638000 has 40 divisors (see below), whose sum is σ = 311051520. Its totient is φ = 51454400.

The previous prime is 128637979. The next prime is 128638001. The reversal of 128638000 is 836821.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 128638000.

It is not an unprimeable number, because it can be changed into a prime (128638001) 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, 30160 + ... + 34159.

It is an arithmetic number, because the mean of its divisors is an integer number (7776288).

Almost surely, 2^128638000 is an apocalyptic number.

128638000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128638000 is an abundant number, since it is smaller than the sum of its proper divisors (182413520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128638000 is an equidigital number, since it uses as much as digits as its factorization.

128638000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64342 (or 64326 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 128638000 is about 11341.8693344616. The cubic root of 128638000 is about 504.8043551521.

The spelling of 128638000 in words is "one hundred twenty-eight million, six hundred thirty-eight thousand".