866772643987 has 2 divisors, whose sum is σ = 866772643988. Its totient is φ = 866772643986.

The previous prime is 866772643883. The next prime is 866772643993. The reversal of 866772643987 is 789346277668.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 866772643987 - 2²⁷ = 866638426259 is a prime.

It is not a weakly prime, because it can be changed into another prime (866772643487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433386321993 + 433386321994.

It is an arithmetic number, because the mean of its divisors is an integer number (433386321994).

Almost surely, 2^866772643987 is an apocalyptic number.

866772643987 is a deficient number, since it is larger than the sum of its proper divisors (1).

866772643987 is an equidigital number, since it uses as much as digits as its factorization.

866772643987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1024192512, while the sum is 73.

The spelling of 866772643987 in words is "eight hundred sixty-six billion, seven hundred seventy-two million, six hundred forty-three thousand, nine hundred eighty-seven".