212008421 has 2 divisors, whose sum is σ = 212008422. Its totient is φ = 212008420.

The previous prime is 212008397. The next prime is 212008439. The reversal of 212008421 is 124800212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 199120321 + 12888100 = 14111^2 + 3590^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212008421 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 212008393 and 212008402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212008451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106004210 + 106004211.

It is an arithmetic number, because the mean of its divisors is an integer number (106004211).

Almost surely, 2^212008421 is an apocalyptic number.

It is an amenable number.

212008421 is a deficient number, since it is larger than the sum of its proper divisors (1).

212008421 is an equidigital number, since it uses as much as digits as its factorization.

212008421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 212008421 is about 14560.5089540167. The cubic root of 212008421 is about 596.2810906645.

Adding to 212008421 its reverse (124800212), we get a palindrome (336808633).

The spelling of 212008421 in words is "two hundred twelve million, eight thousand, four hundred twenty-one".