212421005 has 4 divisors (see below), whose sum is σ = 254905212. Its totient is φ = 169936800.

The previous prime is 212420983. The next prime is 212421019. The reversal of 212421005 is 500124212.

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 96255721 + 116165284 = 9811^2 + 10778^2 .

It is not a de Polignac number, because 212421005 - 2⁶ = 212420941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21242096 + ... + 21242105.

It is an arithmetic number, because the mean of its divisors is an integer number (63726303).

Almost surely, 2^212421005 is an apocalyptic number.

It is an amenable number.

212421005 is a deficient number, since it is larger than the sum of its proper divisors (42484207).

212421005 is an equidigital number, since it uses as much as digits as its factorization.

212421005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42484206.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 212421005 is about 14574.6699791110. The cubic root of 212421005 is about 596.6676423247.

Adding to 212421005 its reverse (500124212), we get a palindrome (712545217).

The spelling of 212421005 in words is "two hundred twelve million, four hundred twenty-one thousand, five".