405208985 has 4 divisors (see below), whose sum is σ = 486250788. Its totient is φ = 324167184.

The previous prime is 405208939. The next prime is 405209017. The reversal of 405208985 is 589802504.

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 185695129 + 219513856 = 13627^2 + 14816^2 .

It is a cyclic number.

It is not a de Polignac number, because 405208985 - 2⁸ = 405208729 is a prime.

It is a Duffinian 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, 40520894 + ... + 40520903.

It is an arithmetic number, because the mean of its divisors is an integer number (121562697).

Almost surely, 2^405208985 is an apocalyptic number.

It is an amenable number.

405208985 is a deficient number, since it is larger than the sum of its proper divisors (81041803).

405208985 is an equidigital number, since it uses as much as digits as its factorization.

405208985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81041802.

The product of its (nonzero) digits is 115200, while the sum is 41.

The square root of 405208985 is about 20129.8034019212. The cubic root of 405208985 is about 739.9908600040.

It can be divided in two parts, 40 and 5208985, that added together give a palindrome (5209025).

The spelling of 405208985 in words is "four hundred five million, two hundred eight thousand, nine hundred eighty-five".