212009999 has 4 divisors (see below), whose sum is σ = 223168440. Its totient is φ = 200851560.

The previous prime is 212009989. The next prime is 212010041. The reversal of 212009999 is 999900212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 212009999 - 2¹² = 212005903 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212009939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5579192 + ... + 5579229.

It is an arithmetic number, because the mean of its divisors is an integer number (55792110).

Almost surely, 2^212009999 is an apocalyptic number.

212009999 is a deficient number, since it is larger than the sum of its proper divisors (11158441).

212009999 is a wasteful number, since it uses less digits than its factorization.

212009999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11158440.

The product of its (nonzero) digits is 26244, while the sum is 41.

The square root of 212009999 is about 14560.5631415821. The cubic root of 212009999 is about 596.2825700542.

The spelling of 212009999 in words is "two hundred twelve million, nine thousand, nine hundred ninety-nine".