812366809 has 2 divisors, whose sum is σ = 812366810. Its totient is φ = 812366808.

The previous prime is 812366747. The next prime is 812366851. The reversal of 812366809 is 908663218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 705699225 + 106667584 = 26565^2 + 10328^2 .

It is a cyclic number.

It is not a de Polignac number, because 812366809 - 2²⁷ = 678149081 is a prime.

It is not a weakly prime, because it can be changed into another prime (812366909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 406183404 + 406183405.

It is an arithmetic number, because the mean of its divisors is an integer number (406183405).

Almost surely, 2^812366809 is an apocalyptic number.

It is an amenable number.

812366809 is a deficient number, since it is larger than the sum of its proper divisors (1).

812366809 is an equidigital number, since it uses as much as digits as its factorization.

812366809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 812366809 is about 28502.0492070307. The cubic root of 812366809 is about 933.0767980186.

The spelling of 812366809 in words is "eight hundred twelve million, three hundred sixty-six thousand, eight hundred nine".