1604401 has 4 divisors (see below), whose sum is σ = 1608804. Its totient is φ = 1600000.

The previous prime is 1604399. The next prime is 1604413. The reversal of 1604401 is 1044061.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1044061 = 67 ⋅15583.

It can be written as a sum of positive squares in 2 ways, for example, as 883600 + 720801 = 940^2 + 849^2 .

It is a 3-Lehmer number, since φ(1604401) divides (1604401-1)³.

It is a cyclic number.

It is not a de Polignac number, because 1604401 - 2¹ = 1604399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1604441) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1600 + ... + 2401.

It is an arithmetic number, because the mean of its divisors is an integer number (402201).

2^1604401 is an apocalyptic number.

It is an amenable number.

1604401 is a deficient number, since it is larger than the sum of its proper divisors (4403).

1604401 is an equidigital number, since it uses as much as digits as its factorization.

1604401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4402.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 1604401 is about 1266.6495174278. The cubic root of 1604401 is about 117.0678497049.

Adding to 1604401 its reverse (1044061), we get a palindrome (2648462).

It can be divided in two parts, 1604 and 401, that multiplied together give a square (643204 = 802²).

The spelling of 1604401 in words is "one million, six hundred four thousand, four hundred one".