409857685 has 4 divisors (see below), whose sum is σ = 491829228. Its totient is φ = 327886144.

The previous prime is 409857671. The next prime is 409857691. The reversal of 409857685 is 586758904.

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 109286116 + 300571569 = 10454^2 + 17337^2 .

It is a cyclic number.

It is not a de Polignac number, because 409857685 - 2¹⁵ = 409824917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 40985764 + ... + 40985773.

It is an arithmetic number, because the mean of its divisors is an integer number (122957307).

Almost surely, 2^409857685 is an apocalyptic number.

It is an amenable number.

409857685 is a deficient number, since it is larger than the sum of its proper divisors (81971543).

409857685 is an equidigital number, since it uses as much as digits as its factorization.

409857685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81971542.

The product of its (nonzero) digits is 2419200, while the sum is 52.

The square root of 409857685 is about 20244.9422078701. The cubic root of 409857685 is about 742.8099187277.

The spelling of 409857685 in words is "four hundred nine million, eight hundred fifty-seven thousand, six hundred eighty-five".