866389556 has 12 divisors (see below), whose sum is σ = 1516531968. Its totient is φ = 433094712.

The previous prime is 866389543. The next prime is 866389577. The reversal of 866389556 is 655983668.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3476 + ... + 41771.

It is an arithmetic number, because the mean of its divisors is an integer number (126377664).

Almost surely, 2^866389556 is an apocalyptic number.

It is an amenable number.

866389556 is a deficient number, since it is larger than the sum of its proper divisors (650142412).

866389556 is a wasteful number, since it uses less digits than its factorization.

866389556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50038 (or 50036 counting only the distinct ones).

The product of its digits is 9331200, while the sum is 56.

The square root of 866389556 is about 29434.4960208256. The cubic root of 866389556 is about 953.3178747337.

The spelling of 866389556 in words is "eight hundred sixty-six million, three hundred eighty-nine thousand, five hundred fifty-six".