42840205 has 4 divisors (see below), whose sum is σ = 51408252. Its totient is φ = 34272160.

The previous prime is 42840173. The next prime is 42840227. The reversal of 42840205 is 50204824.

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 4721929 + 38118276 = 2173^2 + 6174^2 .

It is not a de Polignac number, because 42840205 - 2⁵ = 42840173 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 42840205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4284016 + ... + 4284025.

It is an arithmetic number, because the mean of its divisors is an integer number (12852063).

Almost surely, 2^42840205 is an apocalyptic number.

It is an amenable number.

42840205 is a deficient number, since it is larger than the sum of its proper divisors (8568047).

42840205 is an equidigital number, since it uses as much as digits as its factorization.

42840205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8568046.

The product of its (nonzero) digits is 2560, while the sum is 25.

The square root of 42840205 is about 6545.2429290287. The cubic root of 42840205 is about 349.9052941039.

The spelling of 42840205 in words is "forty-two million, eight hundred forty thousand, two hundred five".