99999666000 has 720 divisors, whose sum is σ = 384353828352. Its totient is φ = 24216192000.

The previous prime is 99999665989. The next prime is 99999666037. The reversal of 99999666000 is 66699999.

It is a tau number, because it is divible by the number of its divisors (720).

It is a super-2 number, since 2×99999666000² (a number of 23 digits) contains 22 as substring.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 215981769 + ... + 215982231.

Almost surely, 2^99999666000 is an apocalyptic number.

99999666000 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 99999666000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (192176914176).

99999666000 is an abundant number, since it is smaller than the sum of its proper divisors (284354162352).

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

99999666000 is a wasteful number, since it uses less digits than its factorization.

99999666000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589 (or 557 counting only the distinct ones).

The product of its (nonzero) digits is 12754584, while the sum is 63.

The spelling of 99999666000 in words is "ninety-nine billion, nine hundred ninety-nine million, six hundred sixty-six thousand".