865422409 has 2 divisors, whose sum is σ = 865422410. Its totient is φ = 865422408.

The previous prime is 865422407. The next prime is 865422461. The reversal of 865422409 is 904224568.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 540702009 + 324720400 = 23253^2 + 18020^2 .

It is a cyclic number.

It is not a de Polignac number, because 865422409 - 2¹ = 865422407 is a prime.

Together with 865422407, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (865422407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432711204 + 432711205.

It is an arithmetic number, because the mean of its divisors is an integer number (432711205).

Almost surely, 2^865422409 is an apocalyptic number.

It is an amenable number.

865422409 is a deficient number, since it is larger than the sum of its proper divisors (1).

865422409 is an equidigital number, since it uses as much as digits as its factorization.

865422409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 138240, while the sum is 40.

The square root of 865422409 is about 29418.0626316554. The cubic root of 865422409 is about 952.9630144196.

The spelling of 865422409 in words is "eight hundred sixty-five million, four hundred twenty-two thousand, four hundred nine".