999906666 has 32 divisors (see below), whose sum is σ = 2203229376. Its totient is φ = 300000000.

The previous prime is 999906653. The next prime is 999906671. The reversal of 999906666 is 666609999.

It is a super-2 number, since 2×999906666² = 1999626681422471112, which contains 22 as substring.

999906666 is a strobogrammatic number because it is the same when read upside-down.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68335 + ... + 81666.

It is an arithmetic number, because the mean of its divisors is an integer number (68850918).

Almost surely, 2^999906666 is an apocalyptic number.

999906666 is an abundant number, since it is smaller than the sum of its proper divisors (1203322710).

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

999906666 is a wasteful number, since it uses less digits than its factorization.

999906666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150118.

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

The square root of 999906666 is about 31621.3008271323. The cubic root of 999906666 is about 999.9688876987.

The spelling of 999906666 in words is "nine hundred ninety-nine million, nine hundred six thousand, six hundred sixty-six".