5561956129 has 2 divisors, whose sum is σ = 5561956130. Its totient is φ = 5561956128.

The previous prime is 5561956093. The next prime is 5561956187. The reversal of 5561956129 is 9216591655.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5420346129 + 141610000 = 73623^2 + 11900^2 .

It is a cyclic number.

It is not a de Polignac number, because 5561956129 - 2²³ = 5553567521 is a prime.

It is not a weakly prime, because it can be changed into another prime (5561956529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2780978064 + 2780978065.

It is an arithmetic number, because the mean of its divisors is an integer number (2780978065).

Almost surely, 2^5561956129 is an apocalyptic number.

It is an amenable number.

5561956129 is a deficient number, since it is larger than the sum of its proper divisors (1).

5561956129 is an equidigital number, since it uses as much as digits as its factorization.

5561956129 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 729000, while the sum is 49.

The square root of 5561956129 is about 74578.5232422847. The cubic root of 5561956129 is about 1771.7775166875. Note that the first 3 decimals are identical.

The spelling of 5561956129 in words is "five billion, five hundred sixty-one million, nine hundred fifty-six thousand, one hundred twenty-nine".