861337409 has 2 divisors, whose sum is σ = 861337410. Its totient is φ = 861337408.

The previous prime is 861337357. The next prime is 861337459. The reversal of 861337409 is 904733168.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 804289600 + 57047809 = 28360^2 + 7553^2 .

It is a cyclic number.

It is not a de Polignac number, because 861337409 - 2²⁰ = 860288833 is a prime.

It is not a weakly prime, because it can be changed into another prime (861337459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430668704 + 430668705.

It is an arithmetic number, because the mean of its divisors is an integer number (430668705).

Almost surely, 2^861337409 is an apocalyptic number.

It is an amenable number.

861337409 is a deficient number, since it is larger than the sum of its proper divisors (1).

861337409 is an equidigital number, since it uses as much as digits as its factorization.

861337409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108864, while the sum is 41.

The square root of 861337409 is about 29348.5503730593. The cubic root of 861337409 is about 951.4612448590.

The spelling of 861337409 in words is "eight hundred sixty-one million, three hundred thirty-seven thousand, four hundred nine".