904561 has 4 divisors (see below), whose sum is σ = 1033792. Its totient is φ = 775332.

The previous prime is 904559. The next prime is 904573. The reversal of 904561 is 165409.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 165409 = 251 ⋅659.

It is a cyclic number.

It is not a de Polignac number, because 904561 - 2¹ = 904559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (904511) 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, 64605 + ... + 64618.

It is an arithmetic number, because the mean of its divisors is an integer number (258448).

2⁹⁰⁴⁵⁶¹ is an apocalyptic number.

It is an amenable number.

904561 is a deficient number, since it is larger than the sum of its proper divisors (129231).

904561 is a wasteful number, since it uses less digits than its factorization.

904561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129230.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 904561 is about 951.0841182566. The cubic root of 904561 is about 96.7117599102.

The spelling of 904561 in words is "nine hundred four thousand, five hundred sixty-one".