561226621 has 4 divisors (see below), whose sum is σ = 561274812. Its totient is φ = 561178432.

The previous prime is 561226609. The next prime is 561226651. The reversal of 561226621 is 126622165.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 126622165 = 5 ⋅25324433.

It can be written as a sum of positive squares in 2 ways, for example, as 177262596 + 383964025 = 13314^2 + 19595^2 .

It is a cyclic number.

It is not a de Polignac number, because 561226621 - 2⁹ = 561226109 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 (561226651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5451 + ... + 33943.

It is an arithmetic number, because the mean of its divisors is an integer number (140318703).

Almost surely, 2^561226621 is an apocalyptic number.

It is an amenable number.

561226621 is a deficient number, since it is larger than the sum of its proper divisors (48191).

561226621 is a wasteful number, since it uses less digits than its factorization.

561226621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48190.

The product of its digits is 8640, while the sum is 31.

The square root of 561226621 is about 23690.2220546790. Note that the first 3 decimals coincide. The cubic root of 561226621 is about 824.8584371736.

Adding to 561226621 its reverse (126622165), we get a palindrome (687848786).

The spelling of 561226621 in words is "five hundred sixty-one million, two hundred twenty-six thousand, six hundred twenty-one".