42505905 has 16 divisors (see below), whose sum is σ = 73241280. Its totient is φ = 20925888.

The previous prime is 42505891. The next prime is 42505913. The reversal of 42505905 is 50950524.

It is a happy number.

It is not a de Polignac number, because 42505905 - 2⁸ = 42505649 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108795 + ... + 109184.

It is an arithmetic number, because the mean of its divisors is an integer number (4577580).

Almost surely, 2^42505905 is an apocalyptic number.

It is an amenable number.

42505905 is a deficient number, since it is larger than the sum of its proper divisors (30735375).

42505905 is a wasteful number, since it uses less digits than its factorization.

42505905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218000.

The product of its (nonzero) digits is 9000, while the sum is 30.

The square root of 42505905 is about 6519.6552822983. The cubic root of 42505905 is about 348.9927640035.

The spelling of 42505905 in words is "forty-two million, five hundred five thousand, nine hundred five".