561626321 has 2 divisors, whose sum is σ = 561626322. Its totient is φ = 561626320.

The previous prime is 561626239. The next prime is 561626353. The reversal of 561626321 is 123626165.

It is an a-pointer prime, because the next prime (561626353) can be obtained adding 561626321 to its sum of digits (32).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 527345296 + 34281025 = 22964^2 + 5855^2 .

It is a cyclic number.

It is not a de Polignac number, because 561626321 - 2²² = 557432017 is a prime.

It is not a weakly prime, because it can be changed into another prime (561626381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280813160 + 280813161.

It is an arithmetic number, because the mean of its divisors is an integer number (280813161).

Almost surely, 2^561626321 is an apocalyptic number.

It is an amenable number.

561626321 is a deficient number, since it is larger than the sum of its proper divisors (1).

561626321 is an equidigital number, since it uses as much as digits as its factorization.

561626321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 32.

The square root of 561626321 is about 23698.6565231027. The cubic root of 561626321 is about 825.0542093550.

The spelling of 561626321 in words is "five hundred sixty-one million, six hundred twenty-six thousand, three hundred twenty-one".