128640442 has 8 divisors (see below), whose sum is σ = 220526496. Its totient is φ = 55131612.

The previous prime is 128640439. The next prime is 128640451. The reversal of 128640442 is 244046821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 4594288 + ... + 4594315.

It is an arithmetic number, because the mean of its divisors is an integer number (27565812).

Almost surely, 2^128640442 is an apocalyptic number.

128640442 is a deficient number, since it is larger than the sum of its proper divisors (91886054).

128640442 is an equidigital number, since it uses as much as digits as its factorization.

128640442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9188612.

The product of its (nonzero) digits is 12288, while the sum is 31.

The square root of 128640442 is about 11341.9769881622. The cubic root of 128640442 is about 504.8075494504.

The spelling of 128640442 in words is "one hundred twenty-eight million, six hundred forty thousand, four hundred forty-two".