866121671 has 2 divisors, whose sum is σ = 866121672. Its totient is φ = 866121670.

The previous prime is 866121647. The next prime is 866121677. The reversal of 866121671 is 176121668.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-866121671 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866121677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433060835 + 433060836.

It is an arithmetic number, because the mean of its divisors is an integer number (433060836).

Almost surely, 2^866121671 is an apocalyptic number.

866121671 is a deficient number, since it is larger than the sum of its proper divisors (1).

866121671 is an equidigital number, since it uses as much as digits as its factorization.

866121671 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192, while the sum is 38.

The square root of 866121671 is about 29429.9451409614. The cubic root of 866121671 is about 953.2196102819.

The spelling of 866121671 in words is "eight hundred sixty-six million, one hundred twenty-one thousand, six hundred seventy-one".