1556120161 has 2 divisors, whose sum is σ = 1556120162. Its totient is φ = 1556120160.

The previous prime is 1556120141. The next prime is 1556120179. The reversal of 1556120161 is 1610216551.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1505440000 + 50680161 = 38800^2 + 7119^2 .

It is a cyclic number.

It is not a de Polignac number, because 1556120161 - 2²³ = 1547731553 is a prime.

It is not a weakly prime, because it can be changed into another prime (1556120141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 778060080 + 778060081.

It is an arithmetic number, because the mean of its divisors is an integer number (778060081).

Almost surely, 2^1556120161 is an apocalyptic number.

It is an amenable number.

1556120161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1556120161 is an equidigital number, since it uses as much as digits as its factorization.

1556120161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1800, while the sum is 28.

The square root of 1556120161 is about 39447.6889183638. The cubic root of 1556120161 is about 1158.8157158790.

The spelling of 1556120161 in words is "one billion, five hundred fifty-six million, one hundred twenty thousand, one hundred sixty-one".