3866691809 has 2 divisors, whose sum is σ = 3866691810. Its totient is φ = 3866691808.

The previous prime is 3866691779. The next prime is 3866691827. The reversal of 3866691809 is 9081966683.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3041853409 + 824838400 = 55153^2 + 28720^2 .

It is a cyclic number.

It is not a de Polignac number, because 3866691809 - 2⁸ = 3866691553 is a prime.

It is not a weakly prime, because it can be changed into another prime (3866691839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1933345904 + 1933345905.

It is an arithmetic number, because the mean of its divisors is an integer number (1933345905).

Almost surely, 2^3866691809 is an apocalyptic number.

It is an amenable number.

3866691809 is a deficient number, since it is larger than the sum of its proper divisors (1).

3866691809 is an equidigital number, since it uses as much as digits as its factorization.

3866691809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3359232, while the sum is 56.

The square root of 3866691809 is about 62182.7291858439. The cubic root of 3866691809 is about 1569.5669771478.

The spelling of 3866691809 in words is "three billion, eight hundred sixty-six million, six hundred ninety-one thousand, eight hundred nine".