3866005021 has 2 divisors, whose sum is σ = 3866005022. Its totient is φ = 3866005020.

The previous prime is 3866005019. The next prime is 3866005049. The reversal of 3866005021 is 1205006683.

3866005021 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2035363225 + 1830641796 = 45115^2 + 42786^2 .

It is an emirp because it is prime and its reverse (1205006683) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3866005021 - 2¹ = 3866005019 is a prime.

Together with 3866005019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3866005001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1933002510 + 1933002511.

It is an arithmetic number, because the mean of its divisors is an integer number (1933002511).

Almost surely, 2^3866005021 is an apocalyptic number.

It is an amenable number.

3866005021 is a deficient number, since it is larger than the sum of its proper divisors (1).

3866005021 is an equidigital number, since it uses as much as digits as its factorization.

3866005021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 3866005021 is about 62177.2066033848. The cubic root of 3866005021 is about 1569.4740446838.

The spelling of 3866005021 in words is "three billion, eight hundred sixty-six million, five thousand, twenty-one".