389807666 has 4 divisors (see below), whose sum is σ = 584711502. Its totient is φ = 194903832.

The previous prime is 389807597. The next prime is 389807669. The reversal of 389807666 is 666708983.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 666708983 = 7229 ⋅92227.

It can be written as a sum of positive squares in only one way, i.e., 228644641 + 161163025 = 15121^2 + 12695^2 .

It is not an unprimeable number, because it can be changed into a prime (389807669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97451915 + ... + 97451918.

Almost surely, 2^389807666 is an apocalyptic number.

389807666 is a deficient number, since it is larger than the sum of its proper divisors (194903836).

389807666 is a wasteful number, since it uses less digits than its factorization.

389807666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194903835.

The product of its (nonzero) digits is 2612736, while the sum is 53.

The square root of 389807666 is about 19743.5474522691. The cubic root of 389807666 is about 730.4942333992.

The spelling of 389807666 in words is "three hundred eighty-nine million, eight hundred seven thousand, six hundred sixty-six".