999699666 has 48 divisors (see below), whose sum is σ = 2348483904. Its totient is φ = 282846816.

The previous prime is 999699653. The next prime is 999699689. The reversal of 999699666 is 666996999.

It is a super-3 number, since 3×999699666³ (a number of 28 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 999699666.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13776 + ... + 46788.

It is an arithmetic number, because the mean of its divisors is an integer number (48926748).

Almost surely, 2^999699666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 999699666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1174241952).

999699666 is an abundant number, since it is smaller than the sum of its proper divisors (1348784238).

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

999699666 is a wasteful number, since it uses less digits than its factorization.

999699666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33135 (or 33128 counting only the distinct ones).

The product of its digits is 76527504, while the sum is 69.

The square root of 999699666 is about 31618.0275475875. The cubic root of 999699666 is about 999.8998786427.

The spelling of 999699666 in words is "nine hundred ninety-nine million, six hundred ninety-nine thousand, six hundred sixty-six".