866772666277668 has 18 divisors (see below), whose sum is σ = 2191008684201974. Its totient is φ = 288924222092544.

The previous prime is 866772666277589. The next prime is 866772666277673.

866772666277668 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in only one way, i.e., 667699811852544 + 199072854425124 = 25839888^2 + 14109318^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12038509253821 + ... + 12038509253892.

Almost surely, 2^{866772666277668} is an apocalyptic number.

It is an amenable number.

866772666277668 is an abundant number, since it is smaller than the sum of its proper divisors (1324236017924306).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

866772666277668 is a wasteful number, since it uses less digits than its factorization.

866772666277668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24077018507723 (or 24077018507718 counting only the distinct ones).

The product of its digits is 172064342016, while the sum is 90.

The spelling of 866772666277668 in words is "eight hundred sixty-six trillion, seven hundred seventy-two billion, six hundred sixty-six million, two hundred seventy-seven thousand, six hundred sixty-eight".