1604440001 has 4 divisors (see below), whose sum is σ = 1604828292. Its totient is φ = 1604051712.

The previous prime is 1604439989. The next prime is 1604440007. The reversal of 1604440001 is 1000444061.

It is a happy number.

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 672053776 + 932386225 = 25924^2 + 30535^2 .

It is a cyclic number.

It is not a de Polignac number, because 1604440001 - 2¹⁰ = 1604438977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1604440007) 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, 187880 + ... + 196233.

It is an arithmetic number, because the mean of its divisors is an integer number (401207073).

Almost surely, 2^1604440001 is an apocalyptic number.

It is an amenable number.

1604440001 is a deficient number, since it is larger than the sum of its proper divisors (388291).

1604440001 is an equidigital number, since it uses as much as digits as its factorization.

1604440001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388290.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 1604440001 is about 40055.4615626883. The cubic root of 1604440001 is about 1170.6879828864.

Adding to 1604440001 its reverse (1000444061), we get a palindrome (2604884062).

The spelling of 1604440001 in words is "one billion, six hundred four million, four hundred forty thousand, one".