3821156561 has 2 divisors, whose sum is σ = 3821156562. Its totient is φ = 3821156560.

The previous prime is 3821156509. The next prime is 3821156593. The reversal of 3821156561 is 1656511283.

3821156561 is digitally balanced in base 3, 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., 3755238400 + 65918161 = 61280^2 + 8119^2 .

It is a cyclic number.

It is not a de Polignac number, because 3821156561 - 2¹⁰ = 3821155537 is a prime.

It is not a weakly prime, because it can be changed into another prime (3821156761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1910578280 + 1910578281.

It is an arithmetic number, because the mean of its divisors is an integer number (1910578281).

Almost surely, 2^3821156561 is an apocalyptic number.

It is an amenable number.

3821156561 is a deficient number, since it is larger than the sum of its proper divisors (1).

3821156561 is an equidigital number, since it uses as much as digits as its factorization.

3821156561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43200, while the sum is 38.

The square root of 3821156561 is about 61815.5042121311. The cubic root of 3821156561 is about 1563.3814118275.

The spelling of 3821156561 in words is "three billion, eight hundred twenty-one million, one hundred fifty-six thousand, five hundred sixty-one".