561104821 has 4 divisors (see below), whose sum is σ = 562932832. Its totient is φ = 559276812.

The previous prime is 561104801. The next prime is 561104851. The reversal of 561104821 is 128401165.

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: 128401165 = 5 ⋅25680233.

It is a cyclic number.

It is not a de Polignac number, because 561104821 - 2¹³ = 561096629 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 561104821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561104801) 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, 913545 + ... + 914158.

It is an arithmetic number, because the mean of its divisors is an integer number (140733208).

Almost surely, 2^561104821 is an apocalyptic number.

It is an amenable number.

561104821 is a deficient number, since it is larger than the sum of its proper divisors (1828011).

561104821 is a wasteful number, since it uses less digits than its factorization.

561104821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1828010.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 561104821 is about 23687.6512343457. The cubic root of 561104821 is about 824.7987613238.

Adding to 561104821 its reverse (128401165), we get a palindrome (689505986).

The spelling of 561104821 in words is "five hundred sixty-one million, one hundred four thousand, eight hundred twenty-one".