2109783857 has 4 divisors (see below), whose sum is σ = 2110742016. Its totient is φ = 2108825700.

The previous prime is 2109783829. The next prime is 2109783931. The reversal of 2109783857 is 7583879012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2109783857 - 2⁸ = 2109783601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2109783157) 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, 475769 + ... + 480182.

It is an arithmetic number, because the mean of its divisors is an integer number (527685504).

Almost surely, 2^2109783857 is an apocalyptic number.

It is an amenable number.

2109783857 is a deficient number, since it is larger than the sum of its proper divisors (958159).

2109783857 is an equidigital number, since it uses as much as digits as its factorization.

2109783857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 958158.

The product of its (nonzero) digits is 846720, while the sum is 50.

The square root of 2109783857 is about 45932.3835327539. The cubic root of 2109783857 is about 1282.5648151743.

The spelling of 2109783857 in words is "two billion, one hundred nine million, seven hundred eighty-three thousand, eight hundred fifty-seven".