9999666 has 32 divisors (see below), whose sum is σ = 22334400.
Its totient is φ = 3316320.
The previous prime is 9999659. The next prime is 9999667. The reversal of 9999666 is 6669999.
It is a super-2 number, since 2×99996662 = 199986640223112, which contains 22 as substring.
It is a Harshad number since it is a multiple of its sum of digits (54).
It is a nude number because it is divisible by every one of its digits.
It is a Curzon number.
It is a nialpdrome in base 10.
It is a zygodrome in base 10.
It is not an unprimeable number, because it can be changed into a prime (9999667) by changing a digit.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14845 + ... + 15503.
It is an arithmetic number, because the mean of its divisors is an integer number (697950).
Almost surely, 29999666 is an apocalyptic number.
9999666 is an abundant number, since it is smaller than the sum of its proper divisors (12334734).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
9999666 is a wasteful number, since it uses less digits than its factorization.
9999666 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 951 (or 945 counting only the distinct ones).
The product of its digits is 1417176, while the sum is 54.
The square root of 9999666 is about 3162.2248496905.
The cubic root of 9999666 is about 215.4410703725.
The spelling of 9999666 in words is "nine million, nine hundred ninety-nine thousand, six hundred sixty-six".