863405666 has 4 divisors (see below), whose sum is σ = 1295108502. Its totient is φ = 431702832.

The previous prime is 863405663. The next prime is 863405689. The reversal of 863405666 is 666504368.

863405666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 791240641 + 72165025 = 28129^2 + 8495^2 .

It is not an unprimeable number, because it can be changed into a prime (863405663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 215851415 + ... + 215851418.

Almost surely, 2^863405666 is an apocalyptic number.

863405666 is a deficient number, since it is larger than the sum of its proper divisors (431702836).

863405666 is a wasteful number, since it uses less digits than its factorization.

863405666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 431702835.

The product of its (nonzero) digits is 622080, while the sum is 44.

The square root of 863405666 is about 29383.7653475520. The cubic root of 863405666 is about 952.2221907116. Note that the first 3 decimals are identical.

The spelling of 863405666 in words is "eight hundred sixty-three million, four hundred five thousand, six hundred sixty-six".