212182409 has 2 divisors, whose sum is σ = 212182410. Its totient is φ = 212182408.

The previous prime is 212182379. The next prime is 212182427. The reversal of 212182409 is 904281212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 201554809 + 10627600 = 14197^2 + 3260^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212182409 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (212182459) by changing a digit.

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 as a sum of consecutive naturals, namely, 106091204 + 106091205.

It is an arithmetic number, because the mean of its divisors is an integer number (106091205).

Almost surely, 2^212182409 is an apocalyptic number.

It is an amenable number.

212182409 is a deficient number, since it is larger than the sum of its proper divisors (1).

212182409 is an equidigital number, since it uses as much as digits as its factorization.

212182409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 212182409 is about 14566.4823825109. The cubic root of 212182409 is about 596.4441618397. Note that the first 3 decimals are identical.

The spelling of 212182409 in words is "two hundred twelve million, one hundred eighty-two thousand, four hundred nine".