2019640109 has 4 divisors (see below), whose sum is σ = 2024677020. Its totient is φ = 2014603200.

The previous prime is 2019640057. The next prime is 2019640123. The reversal of 2019640109 is 9010469102.

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 1947015625 + 72624484 = 44125^2 + 8522^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2019640109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2019640159) 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, 2517854 + ... + 2518655.

It is an arithmetic number, because the mean of its divisors is an integer number (506169255).

Almost surely, 2^2019640109 is an apocalyptic number.

It is an amenable number.

2019640109 is a deficient number, since it is larger than the sum of its proper divisors (5036911).

2019640109 is an equidigital number, since it uses as much as digits as its factorization.

2019640109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5036910.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 2019640109 is about 44940.4061953160. The cubic root of 2019640109 is about 1264.0317876843.

The spelling of 2019640109 in words is "two billion, nineteen million, six hundred forty thousand, one hundred nine".