128640450 has 48 divisors (see below), whose sum is σ = 335826720. Its totient is φ = 32497920.

The previous prime is 128640439. The next prime is 128640451. The reversal of 128640450 is 54046821.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (128640451) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19719 + ... + 25418.

It is an arithmetic number, because the mean of its divisors is an integer number (6996390).

Almost surely, 2^128640450 is an apocalyptic number.

128640450 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

128640450 is an abundant number, since it is smaller than the sum of its proper divisors (207186270).

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

128640450 is a wasteful number, since it uses less digits than its factorization.

128640450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45171 (or 45166 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 128640450 is about 11341.9773408344. The cubic root of 128640450 is about 504.8075599148.

The spelling of 128640450 in words is "one hundred twenty-eight million, six hundred forty thousand, four hundred fifty".