866842397 has 2 divisors, whose sum is σ = 866842398. Its totient is φ = 866842396.

The previous prime is 866842363. The next prime is 866842399. The reversal of 866842397 is 793248668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 567344761 + 299497636 = 23819^2 + 17306^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-866842397 is a prime.

Together with 866842399, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866842399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433421198 + 433421199.

It is an arithmetic number, because the mean of its divisors is an integer number (433421199).

Almost surely, 2^866842397 is an apocalyptic number.

It is an amenable number.

866842397 is a deficient number, since it is larger than the sum of its proper divisors (1).

866842397 is an equidigital number, since it uses as much as digits as its factorization.

866842397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3483648, while the sum is 53.

The square root of 866842397 is about 29442.1873677891. The cubic root of 866842397 is about 953.4839379190.

The spelling of 866842397 in words is "eight hundred sixty-six million, eight hundred forty-two thousand, three hundred ninety-seven".