556615561 has 4 divisors (see below), whose sum is σ = 556664724. Its totient is φ = 556566400.

The previous prime is 556615559. The next prime is 556615597. The reversal of 556615561 is 165516655.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 83814025 + 472801536 = 9155^2 + 21744^2 .

It is a cyclic number.

It is not a de Polignac number, because 556615561 - 2¹ = 556615559 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (556615511) 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 3 ways as a sum of consecutive naturals, for example, 1941 + ... + 33421.

It is an arithmetic number, because the mean of its divisors is an integer number (139166181).

Almost surely, 2^556615561 is an apocalyptic number.

It is an amenable number.

556615561 is a deficient number, since it is larger than the sum of its proper divisors (49163).

556615561 is a wasteful number, since it uses less digits than its factorization.

556615561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49162.

The product of its digits is 135000, while the sum is 40.

The square root of 556615561 is about 23592.7014349777. The cubic root of 556615561 is about 822.5931989130.

The spelling of 556615561 in words is "five hundred fifty-six million, six hundred fifteen thousand, five hundred sixty-one".