404561 has 4 divisors (see below), whose sum is σ = 407652. Its totient is φ = 401472.

The previous prime is 404557. The next prime is 404597. The reversal of 404561 is 165404.

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 286225 + 118336 = 535^2 + 344^2 .

It is a cyclic number.

It is not a de Polignac number, because 404561 - 2² = 404557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (404531) 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, 1340 + ... + 1613.

It is an arithmetic number, because the mean of its divisors is an integer number (101913).

2⁴⁰⁴⁵⁶¹ is an apocalyptic number.

It is an amenable number.

404561 is a deficient number, since it is larger than the sum of its proper divisors (3091).

404561 is a wasteful number, since it uses less digits than its factorization.

404561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3090.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 404561 is about 636.0510985762. The cubic root of 404561 is about 73.9596200442.

Adding to 404561 its reverse (165404), we get a palindrome (569965).

The spelling of 404561 in words is "four hundred four thousand, five hundred sixty-one".