42478917 has 16 divisors (see below), whose sum is σ = 62149248. Its totient is φ = 25646400.

The previous prime is 42478859. The next prime is 42478921. The reversal of 42478917 is 71987424.

It is a happy number.

It is not a de Polignac number, because 42478917 - 2¹⁵ = 42446149 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42478967) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8209 + ... + 12342.

It is an arithmetic number, because the mean of its divisors is an integer number (3884328).

Almost surely, 2^42478917 is an apocalyptic number.

It is an amenable number.

42478917 is a deficient number, since it is larger than the sum of its proper divisors (19670331).

42478917 is a wasteful number, since it uses less digits than its factorization.

42478917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20620.

The product of its digits is 112896, while the sum is 42.

The square root of 42478917 is about 6517.5852123313. The cubic root of 42478917 is about 348.9188871246.

The spelling of 42478917 in words is "forty-two million, four hundred seventy-eight thousand, nine hundred seventeen".