212434309 has 4 divisors (see below), whose sum is σ = 219759660. Its totient is φ = 205108960.

The previous prime is 212434283. The next prime is 212434331. The reversal of 212434309 is 903434212.

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 66096900 + 146337409 = 8130^2 + 12097^2 .

It is a cyclic number.

It is not a de Polignac number, because 212434309 - 2⁷ = 212434181 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212434349) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3662632 + ... + 3662689.

It is an arithmetic number, because the mean of its divisors is an integer number (54939915).

Almost surely, 2^212434309 is an apocalyptic number.

212434309 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

212434309 is a deficient number, since it is larger than the sum of its proper divisors (7325351).

212434309 is an equidigital number, since it uses as much as digits as its factorization.

212434309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7325350.

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 212434309 is about 14575.1263802411. The cubic root of 212434309 is about 596.6800985640.

It can be divided in two parts, 21243 and 4309, that added together give a palindrome (25552).

The spelling of 212434309 in words is "two hundred twelve million, four hundred thirty-four thousand, three hundred nine".