866802109 has 2 divisors, whose sum is σ = 866802110. Its totient is φ = 866802108.

The previous prime is 866802107. The next prime is 866802143. The reversal of 866802109 is 901208668.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 606883225 + 259918884 = 24635^2 + 16122^2 .

It is a cyclic number.

It is not a de Polignac number, because 866802109 - 2¹ = 866802107 is a prime.

Together with 866802107, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866802107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433401054 + 433401055.

It is an arithmetic number, because the mean of its divisors is an integer number (433401055).

Almost surely, 2^866802109 is an apocalyptic number.

It is an amenable number.

866802109 is a deficient number, since it is larger than the sum of its proper divisors (1).

866802109 is an equidigital number, since it uses as much as digits as its factorization.

866802109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 866802109 is about 29441.5031715434. The cubic root of 866802109 is about 953.4691660850.

The spelling of 866802109 in words is "eight hundred sixty-six million, eight hundred two thousand, one hundred nine".