866121677 has 2 divisors, whose sum is σ = 866121678. Its totient is φ = 866121676.

The previous prime is 866121671. The next prime is 866121689. The reversal of 866121677 is 776121668.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 862361956 + 3759721 = 29366^2 + 1939^2 .

It is a cyclic number.

It is not a de Polignac number, because 866121677 - 2¹⁴ = 866105293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866121671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433060838 + 433060839.

It is an arithmetic number, because the mean of its divisors is an integer number (433060839).

Almost surely, 2^866121677 is an apocalyptic number.

It is an amenable number.

866121677 is a deficient number, since it is larger than the sum of its proper divisors (1).

866121677 is an equidigital number, since it uses as much as digits as its factorization.

866121677 is an evil number, because the sum of its binary digits is even.

The product of its digits is 169344, while the sum is 44.

The square root of 866121677 is about 29429.9452428984. The cubic root of 866121677 is about 953.2196124831.

Subtracting from 866121677 its reverse (776121668), we obtain a palindrome (90000009).

The spelling of 866121677 in words is "eight hundred sixty-six million, one hundred twenty-one thousand, six hundred seventy-seven".