212001101000021 has 4 divisors (see below), whose sum is σ = 212001172748172. Its totient is φ = 212001029251872.

The previous prime is 212001101000011. The next prime is 212001101000063. The reversal of 212001101000021 is 120000101100212.

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 14109752127025 + 197891348872996 = 3756295^2 + 14067386^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212001101000021 is a prime.

It is a super-2 number, since 2×212001101000021² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212001100999966 and 212001101000011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212001101000011) 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, 31242566 + ... + 37417911.

It is an arithmetic number, because the mean of its divisors is an integer number (53000293187043).

Almost surely, 2^{212001101000021} is an apocalyptic number.

It is an amenable number.

212001101000021 is a deficient number, since it is larger than the sum of its proper divisors (71748151).

212001101000021 is an equidigital number, since it uses as much as digits as its factorization.

212001101000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71748150.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 212001101000021 its reverse (120000101100212), we get a palindrome (332001202100233).

The spelling of 212001101000021 in words is "two hundred twelve trillion, one billion, one hundred one million, twenty-one", and thus it is an aban number.