212121101999 has 4 divisors (see below), whose sum is σ = 215287088664. Its totient is φ = 208955115336.

The previous prime is 212121101987. The next prime is 212121102001. The reversal of 212121101999 is 999101121212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212121101999 is a prime.

It is a super-3 number, since 3×212121101999³ (a number of 35 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121151999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1582993232 + ... + 1582993365.

It is an arithmetic number, because the mean of its divisors is an integer number (53821772166).

Almost surely, 2^212121101999 is an apocalyptic number.

212121101999 is a deficient number, since it is larger than the sum of its proper divisors (3165986665).

212121101999 is an equidigital number, since it uses as much as digits as its factorization.

212121101999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3165986664.

The product of its (nonzero) digits is 5832, while the sum is 38.

It can be divided in two parts, 21212 and 1101999, that added together give a palindrome (1123211).

The spelling of 212121101999 in words is "two hundred twelve billion, one hundred twenty-one million, one hundred one thousand, nine hundred ninety-nine".