42905 has 4 divisors (see below), whose sum is σ = 51492. Its totient is φ = 34320.

The previous prime is 42901. The next prime is 42923. The reversal of 42905 is 50924.

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 4489 + 38416 = 67^2 + 196^2 .

It is not a de Polignac number, because 42905 - 2² = 42901 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (42901) 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, 4286 + ... + 4295.

It is an arithmetic number, because the mean of its divisors is an integer number (12873).

2⁴²⁹⁰⁵ is an apocalyptic number.

It is an amenable number.

42905 is a deficient number, since it is larger than the sum of its proper divisors (8587).

42905 is an equidigital number, since it uses as much as digits as its factorization.

42905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8586.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 42905 is about 207.1352215341. The cubic root of 42905 is about 35.0081613621.

The spelling of 42905 in words is "forty-two thousand, nine hundred five".