556611561 has 32 divisors (see below), whose sum is σ = 900979200. Its totient is φ = 336813840.

The previous prime is 556611551. The next prime is 556611571. The reversal of 556611561 is 165116655.

It is an interprime number because it is at equal distance from previous prime (556611551) and next prime (556611571).

It is not a de Polignac number, because 556611561 - 2²¹ = 554514409 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (556611521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 280270 + ... + 282248.

It is an arithmetic number, because the mean of its divisors is an integer number (28155600).

Almost surely, 2^556611561 is an apocalyptic number.

It is an amenable number.

556611561 is a deficient number, since it is larger than the sum of its proper divisors (344367639).

556611561 is a wasteful number, since it uses less digits than its factorization.

556611561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2946 (or 2940 counting only the distinct ones).

The product of its digits is 27000, while the sum is 36.

The square root of 556611561 is about 23592.6166628460. The cubic root of 556611561 is about 822.5912284443.

The spelling of 556611561 in words is "five hundred fifty-six million, six hundred eleven thousand, five hundred sixty-one".