2355665561 has 2 divisors, whose sum is σ = 2355665562. Its totient is φ = 2355665560.

The previous prime is 2355665531. The next prime is 2355665591. The reversal of 2355665561 is 1655665532.

It is a balanced prime because it is at equal distance from previous prime (2355665531) and next prime (2355665591).

It can be written as a sum of positive squares in only one way, i.e., 1587544336 + 768121225 = 39844^2 + 27715^2 .

It is a cyclic number.

It is not a de Polignac number, because 2355665561 - 2¹⁰ = 2355664537 is a prime.

It is not a weakly prime, because it can be changed into another prime (2355665531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1177832780 + 1177832781.

It is an arithmetic number, because the mean of its divisors is an integer number (1177832781).

Almost surely, 2^2355665561 is an apocalyptic number.

It is an amenable number.

2355665561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2355665561 is an equidigital number, since it uses as much as digits as its factorization.

2355665561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 810000, while the sum is 44.

The square root of 2355665561 is about 48535.1991960474. The cubic root of 2355665561 is about 1330.5704604308.

The spelling of 2355665561 in words is "two billion, three hundred fifty-five million, six hundred sixty-five thousand, five hundred sixty-one".