212121202111001 has 4 divisors (see below), whose sum is σ = 212124481065252. Its totient is φ = 212117923156752.

The previous prime is 212121202110997. The next prime is 212121202111037. The reversal of 212121202111001 is 100111202121212.

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 81398017747225 + 130723184363776 = 9022085^2 + 11433424^2 .

It is a cyclic number.

It is not a de Polignac number, because 212121202111001 - 2² = 212121202110997 is a prime.

It is a super-2 number, since 2×212121202111001² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212121202111051) 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, 1639380086 + ... + 1639509471.

It is an arithmetic number, because the mean of its divisors is an integer number (53031120266313).

Almost surely, 2^{212121202111001} is an apocalyptic number.

It is an amenable number.

212121202111001 is a deficient number, since it is larger than the sum of its proper divisors (3278954251).

212121202111001 is an equidigital number, since it uses as much as digits as its factorization.

212121202111001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3278954250.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 212121202111001 its reverse (100111202121212), we get a palindrome (312232404232213).

It can be divided in two parts, 21212120211 and 1001, that added together give a palindrome (21212121212).

The spelling of 212121202111001 in words is "two hundred twelve trillion, one hundred twenty-one billion, two hundred two million, one hundred eleven thousand, one".