409123685 has 4 divisors (see below), whose sum is σ = 490948428. Its totient is φ = 327298944.

The previous prime is 409123681. The next prime is 409123691. The reversal of 409123685 is 586321904.

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 196168036 + 212955649 = 14006^2 + 14593^2 .

It is a cyclic number.

It is not a de Polignac number, because 409123685 - 2² = 409123681 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (409123681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40912364 + ... + 40912373.

It is an arithmetic number, because the mean of its divisors is an integer number (122737107).

Almost surely, 2^409123685 is an apocalyptic number.

It is an amenable number.

409123685 is a deficient number, since it is larger than the sum of its proper divisors (81824743).

409123685 is an equidigital number, since it uses as much as digits as its factorization.

409123685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81824742.

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 409123685 is about 20226.8060998270. The cubic root of 409123685 is about 742.3662295335.

The spelling of 409123685 in words is "four hundred nine million, one hundred twenty-three thousand, six hundred eighty-five".