999900000006666 has 128 divisors (see below), whose sum is σ = 2223680185774080. Its totient is φ = 297211965984000.

The previous prime is 999900000006631. The next prime is 999900000006673. The reversal of 999900000006666 is 666600000009999.

999900000006666 is a strobogrammatic number because it is the same when read upside-down.

It is a zygodrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6381596761 + ... + 6381753443.

It is an arithmetic number, because the mean of its divisors is an integer number (17372501451360).

Almost surely, 2^{999900000006666} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 999900000006666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1111840092887040).

999900000006666 is an abundant number, since it is smaller than the sum of its proper divisors (1223780185767414).

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

999900000006666 is a wasteful number, since it uses less digits than its factorization.

999900000006666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165692.

The product of its (nonzero) digits is 8503056, while the sum is 60.

The spelling of 999900000006666 in words is "nine hundred ninety-nine trillion, nine hundred billion, six thousand, six hundred sixty-six".