405685643 has 4 divisors (see below), whose sum is σ = 442566168. Its totient is φ = 368805120.

The previous prime is 405685597. The next prime is 405685673. The reversal of 405685643 is 346586504.

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

It is a cyclic number.

It is not a de Polignac number, because 405685643 - 2¹⁰ = 405684619 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 405685643.

It is not an unprimeable number, because it can be changed into a prime (405685673) 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, 18440246 + ... + 18440267.

It is an arithmetic number, because the mean of its divisors is an integer number (110641542).

Almost surely, 2^405685643 is an apocalyptic number.

405685643 is a deficient number, since it is larger than the sum of its proper divisors (36880525).

405685643 is a wasteful number, since it uses less digits than its factorization.

405685643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36880524.

The product of its (nonzero) digits is 345600, while the sum is 41.

The square root of 405685643 is about 20141.6395310809. The cubic root of 405685643 is about 740.2809032172.

The spelling of 405685643 in words is "four hundred five million, six hundred eighty-five thousand, six hundred forty-three".