212000021 has 2 divisors, whose sum is σ = 212000022. Its totient is φ = 212000020.

The previous prime is 212000003. The next prime is 212000029. The reversal of 212000021 is 120000212.

212000021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (212000029) can be obtained adding 212000021 to its sum of digits (8).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 176597521 + 35402500 = 13289^2 + 5950^2 .

It is a cyclic number.

It is not a de Polignac number, because 212000021 - 2²⁶ = 144891157 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 211999972 and 212000008.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212000029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106000010 + 106000011.

It is an arithmetic number, because the mean of its divisors is an integer number (106000011).

Almost surely, 2^212000021 is an apocalyptic number.

It is an amenable number.

212000021 is a deficient number, since it is larger than the sum of its proper divisors (1).

212000021 is an equidigital number, since it uses as much as digits as its factorization.

212000021 is an evil number, because the sum of its binary digits is even.

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

The square root of 212000021 is about 14560.2204997040. The cubic root of 212000021 is about 596.2732154626.

Adding to 212000021 its reverse (120000212), we get a palindrome (332000233).

It can be divided in two parts, 2 and 12000021, that multiplied together give a palindrome (24000042).

The spelling of 212000021 in words is "two hundred twelve million, twenty-one", and thus it is an aban number.