999111666 has 64 divisors (see below), whose sum is σ = 2393452800. Its totient is φ = 277724160.

The previous prime is 999111661. The next prime is 999111677. The reversal of 999111666 is 666111999.

It is a super-2 number, since 2×999111666² = 1996448242274591112, which contains 22 as substring.

999111666 is a strobogrammatic number because it is the same when read upside-down.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (999111661) 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 in 31 ways as a sum of consecutive naturals, for example, 69586 + ... + 82706.

It is an arithmetic number, because the mean of its divisors is an integer number (37397700).

Almost surely, 2^999111666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 999111666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1196726400).

999111666 is an abundant number, since it is smaller than the sum of its proper divisors (1394341134).

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

999111666 is a wasteful number, since it uses less digits than its factorization.

999111666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13184 (or 13170 counting only the distinct ones).

The product of its digits is 157464, while the sum is 48.

The square root of 999111666 is about 31608.7276871436. The cubic root of 999111666 is about 999.7038009414.

The spelling of 999111666 in words is "nine hundred ninety-nine million, one hundred eleven thousand, six hundred sixty-six".