3865819 has 2 divisors, whose sum is σ = 3865820. Its totient is φ = 3865818.

The previous prime is 3865801. The next prime is 3865847. The reversal of 3865819 is 9185683.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 3865819 - 2⁷ = 3865691 is a prime.

It is a super-2 number, since 2×3865819² = 29889113081522, which contains 22 as substring.

It is a Chen prime.

3865819 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (3865859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1932909 + 1932910.

It is an arithmetic number, because the mean of its divisors is an integer number (1932910).

Almost surely, 2^3865819 is an apocalyptic number.

3865819 is a deficient number, since it is larger than the sum of its proper divisors (1).

3865819 is an equidigital number, since it uses as much as digits as its factorization.

3865819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 40.

The square root of 3865819 is about 1966.1686092500. The cubic root of 3865819 is about 156.9448871427.

The spelling of 3865819 in words is "three million, eight hundred sixty-five thousand, eight hundred nineteen".