128320645 has 8 divisors (see below), whose sum is σ = 155715480. Its totient is φ = 101502720.

The previous prime is 128320631. The next prime is 128320651. The reversal of 128320645 is 546023821.

It can be written as a sum of positive squares in 4 ways, for example, as 19368801 + 108951844 = 4401^2 + 10438^2 .

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

It is not a de Polignac number, because 128320645 - 2⁵ = 128320613 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 143736 + ... + 144625.

It is an arithmetic number, because the mean of its divisors is an integer number (19464435).

Almost surely, 2^128320645 is an apocalyptic number.

It is an amenable number.

128320645 is a deficient number, since it is larger than the sum of its proper divisors (27394835).

128320645 is an equidigital number, since it uses as much as digits as its factorization.

128320645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288455.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 128320645 is about 11327.8702764465. The cubic root of 128320645 is about 504.3888892486.

The spelling of 128320645 in words is "one hundred twenty-eight million, three hundred twenty thousand, six hundred forty-five".