857018609 has 4 divisors (see below), whose sum is σ = 857526516. Its totient is φ = 856510704.

The previous prime is 857018597. The next prime is 857018611. The reversal of 857018609 is 906810758.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 118701025 + 738317584 = 10895^2 + 27172^2 .

It is a cyclic number.

It is not a de Polignac number, because 857018609 - 2⁴ = 857018593 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 857018609.

It is not an unprimeable number, because it can be changed into a prime (857018689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 251414 + ... + 254799.

It is an arithmetic number, because the mean of its divisors is an integer number (214381629).

Almost surely, 2^857018609 is an apocalyptic number.

It is an amenable number.

857018609 is a deficient number, since it is larger than the sum of its proper divisors (507907).

857018609 is a wasteful number, since it uses less digits than its factorization.

857018609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 507906.

The product of its (nonzero) digits is 120960, while the sum is 44.

The square root of 857018609 is about 29274.8801705489. The cubic root of 857018609 is about 949.8683507322.

The spelling of 857018609 in words is "eight hundred fifty-seven million, eighteen thousand, six hundred nine".