212000001821 has 2 divisors, whose sum is σ = 212000001822. Its totient is φ = 212000001820.

The previous prime is 212000001803. The next prime is 212000001841. The reversal of 212000001821 is 128100000212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 195553221796 + 16446780025 = 442214^2 + 128245^2 .

It is a cyclic number.

It is not a de Polignac number, because 212000001821 - 2¹⁴ = 211999985437 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 212000001821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212000001841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106000000910 + 106000000911.

It is an arithmetic number, because the mean of its divisors is an integer number (106000000911).

Almost surely, 2^212000001821 is an apocalyptic number.

It is an amenable number.

212000001821 is a deficient number, since it is larger than the sum of its proper divisors (1).

212000001821 is an equidigital number, since it uses as much as digits as its factorization.

212000001821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 17.

The spelling of 212000001821 in words is "two hundred twelve billion, one thousand, eight hundred twenty-one".