853781609 has 2 divisors, whose sum is σ = 853781610. Its totient is φ = 853781608.

The previous prime is 853781573. The next prime is 853781699. The reversal of 853781609 is 906187358.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 517426009 + 336355600 = 22747^2 + 18340^2 .

It is a cyclic number.

It is not a de Polignac number, because 853781609 - 2⁸ = 853781353 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (853781699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 426890804 + 426890805.

It is an arithmetic number, because the mean of its divisors is an integer number (426890805).

Almost surely, 2^853781609 is an apocalyptic number.

It is an amenable number.

853781609 is a deficient number, since it is larger than the sum of its proper divisors (1).

853781609 is an equidigital number, since it uses as much as digits as its factorization.

853781609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 362880, while the sum is 47.

The square root of 853781609 is about 29219.5415604010. The cubic root of 853781609 is about 948.6709426135.

The spelling of 853781609 in words is "eight hundred fifty-three million, seven hundred eighty-one thousand, six hundred nine".