212043809 has 2 divisors, whose sum is σ = 212043810. Its totient is φ = 212043808.

The previous prime is 212043791. The next prime is 212043833. The reversal of 212043809 is 908340212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 169728784 + 42315025 = 13028^2 + 6505^2 .

It is a cyclic number.

It is not a de Polignac number, because 212043809 - 2²⁰ = 210995233 is a prime.

It is not a weakly prime, because it can be changed into another prime (212043859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106021904 + 106021905.

It is an arithmetic number, because the mean of its divisors is an integer number (106021905).

Almost surely, 2^212043809 is an apocalyptic number.

It is an amenable number.

212043809 is a deficient number, since it is larger than the sum of its proper divisors (1).

212043809 is an equidigital number, since it uses as much as digits as its factorization.

212043809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 212043809 is about 14561.7241080856. The cubic root of 212043809 is about 596.3142654808.

The spelling of 212043809 in words is "two hundred twelve million, forty-three thousand, eight hundred nine".