866807364321749 has 2 divisors, whose sum is σ = 866807364321750. Its totient is φ = 866807364321748.

The previous prime is 866807364321727. The next prime is 866807364321779. The reversal of 866807364321749 is 947123463708668.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 735106906251025 + 131700458070724 = 27112855^2 + 11476082^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-866807364321749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866807364321709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433403682160874 + 433403682160875.

It is an arithmetic number, because the mean of its divisors is an integer number (433403682160875).

Almost surely, 2^{866807364321749} is an apocalyptic number.

It is an amenable number.

866807364321749 is a deficient number, since it is larger than the sum of its proper divisors (1).

866807364321749 is an equidigital number, since it uses as much as digits as its factorization.

866807364321749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1755758592, while the sum is 74.

The spelling of 866807364321749 in words is "eight hundred sixty-six trillion, eight hundred seven billion, three hundred sixty-four million, three hundred twenty-one thousand, seven hundred forty-nine".