3856391389 has 2 divisors, whose sum is σ = 3856391390. Its totient is φ = 3856391388.

The previous prime is 3856391369. The next prime is 3856391417. The reversal of 3856391389 is 9831936583.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3854547225 + 1844164 = 62085^2 + 1358^2 .

It is a cyclic number.

It is not a de Polignac number, because 3856391389 - 2⁹ = 3856390877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3856391309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1928195694 + 1928195695.

It is an arithmetic number, because the mean of its divisors is an integer number (1928195695).

Almost surely, 2^3856391389 is an apocalyptic number.

It is an amenable number.

3856391389 is a deficient number, since it is larger than the sum of its proper divisors (1).

3856391389 is an equidigital number, since it uses as much as digits as its factorization.

3856391389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4199040, while the sum is 55.

The square root of 3856391389 is about 62099.8501527983. The cubic root of 3856391389 is about 1568.1720227513.

The spelling of 3856391389 in words is "three billion, eight hundred fifty-six million, three hundred ninety-one thousand, three hundred eighty-nine".