561611557 has 16 divisors (see below), whose sum is σ = 645386560. Its totient is φ = 484382592.

The previous prime is 561611551. The next prime is 561611579. The reversal of 561611557 is 755116165.

It is a cyclic number.

It is not a de Polignac number, because 561611557 - 2³ = 561611549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561611551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2458 + ... + 33604.

It is an arithmetic number, because the mean of its divisors is an integer number (40336660).

Almost surely, 2^561611557 is an apocalyptic number.

It is an amenable number.

561611557 is a deficient number, since it is larger than the sum of its proper divisors (83775003).

561611557 is a wasteful number, since it uses less digits than its factorization.

561611557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31252.

The product of its digits is 31500, while the sum is 37.

The square root of 561611557 is about 23698.3450266047. The cubic root of 561611557 is about 825.0469796326.

The spelling of 561611557 in words is "five hundred sixty-one million, six hundred eleven thousand, five hundred fifty-seven".