561001109 has 2 divisors, whose sum is σ = 561001110. Its totient is φ = 561001108.

The previous prime is 561001057. The next prime is 561001157. The reversal of 561001109 is 901100165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 361570225 + 199430884 = 19015^2 + 14122^2 .

It is a cyclic number.

It is not a de Polignac number, because 561001109 - 2²⁴ = 544223893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561001159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280500554 + 280500555.

It is an arithmetic number, because the mean of its divisors is an integer number (280500555).

Almost surely, 2^561001109 is an apocalyptic number.

It is an amenable number.

561001109 is a deficient number, since it is larger than the sum of its proper divisors (1).

561001109 is an equidigital number, since it uses as much as digits as its factorization.

561001109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 270, while the sum is 23.

The square root of 561001109 is about 23685.4619756508. The cubic root of 561001109 is about 824.7479408729.

The spelling of 561001109 in words is "five hundred sixty-one million, one thousand, one hundred nine".