8199727909 has 4 divisors (see below), whose sum is σ = 8334149740. Its totient is φ = 8065306080.

The previous prime is 8199727871. The next prime is 8199727957. The reversal of 8199727909 is 9097279918.

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 2888525025 + 5311202884 = 53745^2 + 72878^2 .

It is a cyclic number.

It is not a de Polignac number, because 8199727909 - 2¹⁷ = 8199596837 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (61), and also a Moran number because the ratio is a prime number: 134421769 = 8199727909 / (8 + 1 + 9 + 9 + 7 + 2 + 7 + 9 + 0 + 9).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8199727979) 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, 67210824 + ... + 67210945.

It is an arithmetic number, because the mean of its divisors is an integer number (2083537435).

Almost surely, 2^8199727909 is an apocalyptic number.

It is an amenable number.

8199727909 is a deficient number, since it is larger than the sum of its proper divisors (134421831).

8199727909 is a wasteful number, since it uses less digits than its factorization.

8199727909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134421830.

The product of its (nonzero) digits is 5143824, while the sum is 61.

The square root of 8199727909 is about 90552.3489976930. The cubic root of 8199727909 is about 2016.5073709236.

The spelling of 8199727909 in words is "eight billion, one hundred ninety-nine million, seven hundred twenty-seven thousand, nine hundred nine".