3891919109 has 4 divisors (see below), whose sum is σ = 4191297516. Its totient is φ = 3592540704.

The previous prime is 3891919099. The next prime is 3891919147. The reversal of 3891919109 is 9019191983.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1219546084 + 2672373025 = 34922^2 + 51695^2 .

It is a cyclic number.

It is not a de Polignac number, because 3891919109 - 2²⁸ = 3623483653 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3891919159) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 149689184 + ... + 149689209.

It is an arithmetic number, because the mean of its divisors is an integer number (1047824379).

Almost surely, 2^3891919109 is an apocalyptic number.

It is an amenable number.

3891919109 is a deficient number, since it is larger than the sum of its proper divisors (299378407).

3891919109 is a wasteful number, since it uses less digits than its factorization.

3891919109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299378406.

The product of its (nonzero) digits is 157464, while the sum is 50.

The square root of 3891919109 is about 62385.2475269594. The cubic root of 3891919109 is about 1572.9730012406.

The spelling of 3891919109 in words is "three billion, eight hundred ninety-one million, nine hundred nineteen thousand, one hundred nine".