3855081821 has 2 divisors, whose sum is σ = 3855081822. Its totient is φ = 3855081820.

The previous prime is 3855081809. The next prime is 3855081833. The reversal of 3855081821 is 1281805583.

It is a balanced prime because it is at equal distance from previous prime (3855081809) and next prime (3855081833).

It can be written as a sum of positive squares in only one way, i.e., 3834705625 + 20376196 = 61925^2 + 4514^2 .

It is a cyclic number.

It is not a de Polignac number, because 3855081821 - 2⁶ = 3855081757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3855081871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1927540910 + 1927540911.

It is an arithmetic number, because the mean of its divisors is an integer number (1927540911).

Almost surely, 2^3855081821 is an apocalyptic number.

It is an amenable number.

3855081821 is a deficient number, since it is larger than the sum of its proper divisors (1).

3855081821 is an equidigital number, since it uses as much as digits as its factorization.

3855081821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 76800, while the sum is 41.

The square root of 3855081821 is about 62089.3052062914. The cubic root of 3855081821 is about 1567.9944940554.

The spelling of 3855081821 in words is "three billion, eight hundred fifty-five million, eighty-one thousand, eight hundred twenty-one".