212121000001 has 4 divisors (see below), whose sum is σ = 214307814532. Its totient is φ = 209934185472.

The previous prime is 212120999929. The next prime is 212121000029. The reversal of 212121000001 is 100000121212.

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

It can be written as a sum of positive squares in 2 ways, for example, as 164573016976 + 47547983025 = 405676^2 + 218055^2 .

It is a cyclic number.

It is not a de Polignac number, because 212121000001 - 2¹¹ = 212120997953 is a prime.

It is a super-3 number, since 3×212121000001³ (a number of 35 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212121000031) 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, 1093407120 + ... + 1093407313.

It is an arithmetic number, because the mean of its divisors is an integer number (53576953633).

Almost surely, 2^212121000001 is an apocalyptic number.

It is an amenable number.

212121000001 is a deficient number, since it is larger than the sum of its proper divisors (2186814531).

212121000001 is an equidigital number, since it uses as much as digits as its factorization.

212121000001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2186814530.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 212121000001 its reverse (100000121212), we get a palindrome (312121121213).

It can be divided in two parts, 21212 and 1000001, that multiplied together give a palindrome (21212021212).

The spelling of 212121000001 in words is "two hundred twelve billion, one hundred twenty-one million, one", and thus it is an aban number.