561384661 has 2 divisors, whose sum is σ = 561384662. Its totient is φ = 561384660.

The previous prime is 561384643. The next prime is 561384679. The reversal of 561384661 is 166483165.

It is a balanced prime because it is at equal distance from previous prime (561384643) and next prime (561384679).

It can be written as a sum of positive squares in only one way, i.e., 515063025 + 46321636 = 22695^2 + 6806^2 .

It is a cyclic number.

It is not a de Polignac number, because 561384661 - 2¹⁵ = 561351893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561384641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280692330 + 280692331.

It is an arithmetic number, because the mean of its divisors is an integer number (280692331).

Almost surely, 2^561384661 is an apocalyptic number.

It is an amenable number.

561384661 is a deficient number, since it is larger than the sum of its proper divisors (1).

561384661 is an equidigital number, since it uses as much as digits as its factorization.

561384661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 40.

The square root of 561384661 is about 23693.5573732608. The cubic root of 561384661 is about 824.9358559251.

The spelling of 561384661 in words is "five hundred sixty-one million, three hundred eighty-four thousand, six hundred sixty-one".