561551611 has 2 divisors, whose sum is σ = 561551612. Its totient is φ = 561551610.

The previous prime is 561551603. The next prime is 561551657. The reversal of 561551611 is 116155165.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 561551611 - 2³ = 561551603 is a prime.

It is not a weakly prime, because it can be changed into another prime (561551311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280775805 + 280775806.

It is an arithmetic number, because the mean of its divisors is an integer number (280775806).

Almost surely, 2^561551611 is an apocalyptic number.

561551611 is a deficient number, since it is larger than the sum of its proper divisors (1).

561551611 is an equidigital number, since it uses as much as digits as its factorization.

561551611 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4500, while the sum is 31.

The square root of 561551611 is about 23697.0802209893. The cubic root of 561551611 is about 825.0176236211.

The spelling of 561551611 in words is "five hundred sixty-one million, five hundred fifty-one thousand, six hundred eleven".