3855506561 has 2 divisors, whose sum is σ = 3855506562. Its totient is φ = 3855506560.

The previous prime is 3855506531. The next prime is 3855506563. The reversal of 3855506561 is 1656055583.

3855506561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3842140225 + 13366336 = 61985^2 + 3656^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3855506561 is a prime.

Together with 3855506563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3855506563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1927753280 + 1927753281.

It is an arithmetic number, because the mean of its divisors is an integer number (1927753281).

Almost surely, 2^3855506561 is an apocalyptic number.

It is an amenable number.

3855506561 is a deficient number, since it is larger than the sum of its proper divisors (1).

3855506561 is an equidigital number, since it uses as much as digits as its factorization.

3855506561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 540000, while the sum is 44.

The square root of 3855506561 is about 62092.7255079047. The cubic root of 3855506561 is about 1568.0520774008.

The spelling of 3855506561 in words is "three billion, eight hundred fifty-five million, five hundred six thousand, five hundred sixty-one".