561006421 has 4 divisors (see below), whose sum is σ = 580351500. Its totient is φ = 541661344.

The previous prime is 561006401. The next prime is 561006437. The reversal of 561006421 is 124600165.

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 240095025 + 320911396 = 15495^2 + 17914^2 .

It is a cyclic number.

It is not a de Polignac number, because 561006421 - 2⁵ = 561006389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561006401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9672496 + ... + 9672553.

It is an arithmetic number, because the mean of its divisors is an integer number (145087875).

Almost surely, 2^561006421 is an apocalyptic number.

It is an amenable number.

561006421 is a deficient number, since it is larger than the sum of its proper divisors (19345079).

561006421 is a wasteful number, since it uses less digits than its factorization.

561006421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19345078.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 561006421 is about 23685.5741116824. The cubic root of 561006421 is about 824.7505439855.

Adding to 561006421 its reverse (124600165), we get a palindrome (685606586).

The spelling of 561006421 in words is "five hundred sixty-one million, six thousand, four hundred twenty-one".