989855666 has 16 divisors (see below), whose sum is σ = 1564968600. Its totient is φ = 468843648.

The previous prime is 989855639. The next prime is 989855677. The reversal of 989855666 is 666558989.

It can be written as a sum of positive squares in 4 ways, for example, as 793267225 + 196588441 = 28165^2 + 14021^2 .

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 989855599 and 989855608.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 157931 + ... + 164078.

Almost surely, 2^989855666 is an apocalyptic number.

989855666 is a deficient number, since it is larger than the sum of its proper divisors (575112934).

989855666 is a wasteful number, since it uses less digits than its factorization.

989855666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322093.

The product of its digits is 27993600, while the sum is 62.

The square root of 989855666 is about 31461.9717436781. The cubic root of 989855666 is about 996.6070562862.

The spelling of 989855666 in words is "nine hundred eighty-nine million, eight hundred fifty-five thousand, six hundred sixty-six".