42905909 has 4 divisors (see below), whose sum is σ = 45429804. Its totient is φ = 40382016.

The previous prime is 42905899. The next prime is 42905917. The reversal of 42905909 is 90950924.

42905909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 21022225 + 21883684 = 4585^2 + 4678^2 .

It is a cyclic number.

It is not a de Polignac number, because 42905909 - 2¹⁶ = 42840373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42905999) 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, 1261922 + ... + 1261955.

It is an arithmetic number, because the mean of its divisors is an integer number (11357451).

Almost surely, 2^42905909 is an apocalyptic number.

It is an amenable number.

42905909 is a deficient number, since it is larger than the sum of its proper divisors (2523895).

42905909 is a wasteful number, since it uses less digits than its factorization.

42905909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2523894.

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 42905909 is about 6550.2602238384. The cubic root of 42905909 is about 350.0840859196.

The spelling of 42905909 in words is "forty-two million, nine hundred five thousand, nine hundred nine".