128321680 has 20 divisors (see below), whose sum is σ = 298348092. Its totient is φ = 51328640.

The previous prime is 128321671. The next prime is 128321681. The reversal of 128321680 is 86123821.

It can be written as a sum of positive squares in 2 ways, for example, as 13660416 + 114661264 = 3696^2 + 10708^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (128321681) 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, 801931 + ... + 802090.

Almost surely, 2^128321680 is an apocalyptic number.

128321680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128321680 is an abundant number, since it is smaller than the sum of its proper divisors (170026412).

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

128321680 is a wasteful number, since it uses less digits than its factorization.

128321680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1604034 (or 1604028 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 128321680 is about 11327.9159601402. The cubic root of 128321680 is about 504.3902453336.

The spelling of 128321680 in words is "one hundred twenty-eight million, three hundred twenty-one thousand, six hundred eighty".