383728321 has 4 divisors (see below), whose sum is σ = 390968532. Its totient is φ = 376488112.

The previous prime is 383728277. The next prime is 383728327. The reversal of 383728321 is 123827383.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 167961600 + 215766721 = 12960^2 + 14689^2 .

It is a cyclic number.

It is not a de Polignac number, because 383728321 - 2¹⁹ = 383204033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (383728327) by changing a digit.

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, 3620026 + ... + 3620131.

It is an arithmetic number, because the mean of its divisors is an integer number (97742133).

Almost surely, 2^383728321 is an apocalyptic number.

It is an amenable number.

383728321 is a deficient number, since it is larger than the sum of its proper divisors (7240211).

383728321 is an equidigital number, since it uses as much as digits as its factorization.

383728321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7240210.

The product of its digits is 48384, while the sum is 37.

The square root of 383728321 is about 19588.9846852766. The cubic root of 383728321 is about 726.6767822802.

The spelling of 383728321 in words is "three hundred eighty-three million, seven hundred twenty-eight thousand, three hundred twenty-one".