866141609 has 2 divisors, whose sum is σ = 866141610. Its totient is φ = 866141608.

The previous prime is 866141597. The next prime is 866141641. The reversal of 866141609 is 906141668.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 848265625 + 17875984 = 29125^2 + 4228^2 .

It is a cyclic number.

It is not a de Polignac number, because 866141609 - 2¹² = 866137513 is a prime.

It is a super-2 number, since 2×866141609² = 1500402573682217762, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (866141699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433070804 + 433070805.

It is an arithmetic number, because the mean of its divisors is an integer number (433070805).

Almost surely, 2^866141609 is an apocalyptic number.

It is an amenable number.

866141609 is a deficient number, since it is larger than the sum of its proper divisors (1).

866141609 is an equidigital number, since it uses as much as digits as its factorization.

866141609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 866141609 is about 29430.2838756272. The cubic root of 866141609 is about 953.2269245533.

The spelling of 866141609 in words is "eight hundred sixty-six million, one hundred forty-one thousand, six hundred nine".