212440409 has 4 divisors (see below), whose sum is σ = 215000016. Its totient is φ = 209880804.

The previous prime is 212440391. The next prime is 212440411. The reversal of 212440409 is 904044212.

212440409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 212440409 - 2¹⁶ = 212374873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212440429) 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, 1279679 + ... + 1279844.

It is an arithmetic number, because the mean of its divisors is an integer number (53750004).

Almost surely, 2^212440409 is an apocalyptic number.

It is an amenable number.

212440409 is a deficient number, since it is larger than the sum of its proper divisors (2559607).

212440409 is an equidigital number, since it uses as much as digits as its factorization.

212440409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2559606.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 212440409 is about 14575.3356393601. The cubic root of 212440409 is about 596.6858096844.

The spelling of 212440409 in words is "two hundred twelve million, four hundred forty thousand, four hundred nine".