2168357909 has 4 divisors (see below), whose sum is σ = 2198061516. Its totient is φ = 2138654304.

The previous prime is 2168357839. The next prime is 2168357923. The reversal of 2168357909 is 9097538612.

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 1824144100 + 344213809 = 42710^2 + 18553^2 .

It is a cyclic number.

It is not a de Polignac number, because 2168357909 - 2²⁴ = 2151580693 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 (2168357999) 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, 14851694 + ... + 14851839.

It is an arithmetic number, because the mean of its divisors is an integer number (549515379).

Almost surely, 2^2168357909 is an apocalyptic number.

It is an amenable number.

2168357909 is a deficient number, since it is larger than the sum of its proper divisors (29703607).

2168357909 is an equidigital number, since it uses as much as digits as its factorization.

2168357909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29703606.

The product of its (nonzero) digits is 816480, while the sum is 50.

The square root of 2168357909 is about 46565.6301256624. The cubic root of 2168357909 is about 1294.3259430929.

The spelling of 2168357909 in words is "two billion, one hundred sixty-eight million, three hundred fifty-seven thousand, nine hundred nine".