861134909 has 2 divisors, whose sum is σ = 861134910. Its totient is φ = 861134908.

The previous prime is 861134887. The next prime is 861134917. The reversal of 861134909 is 909431168.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 630763225 + 230371684 = 25115^2 + 15178^2 .

It is a cyclic number.

It is not a de Polignac number, because 861134909 - 2⁸ = 861134653 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (861134959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430567454 + 430567455.

It is an arithmetic number, because the mean of its divisors is an integer number (430567455).

Almost surely, 2^861134909 is an apocalyptic number.

It is an amenable number.

861134909 is a deficient number, since it is larger than the sum of its proper divisors (1).

861134909 is an equidigital number, since it uses as much as digits as its factorization.

861134909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 861134909 is about 29345.1002554089. The cubic root of 861134909 is about 951.3866763252.

The spelling of 861134909 in words is "eight hundred sixty-one million, one hundred thirty-four thousand, nine hundred nine".