128486640 has 40 divisors (see below), whose sum is σ = 398309328. Its totient is φ = 34263040.

The previous prime is 128486621. The next prime is 128486707. The reversal of 128486640 is 46684821.

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

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 267441 + ... + 267920.

Almost surely, 2^128486640 is an apocalyptic number.

128486640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128486640 is an abundant number, since it is smaller than the sum of its proper divisors (269822688).

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

128486640 is a wasteful number, since it uses less digits than its factorization.

128486640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 535377 (or 535371 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 39.

The square root of 128486640 is about 11335.1947490989. The cubic root of 128486640 is about 504.6062872546.

The spelling of 128486640 in words is "one hundred twenty-eight million, four hundred eighty-six thousand, six hundred forty".