42278391 has 6 divisors (see below), whose sum is σ = 61068800. Its totient is φ = 28185588.

The previous prime is 42278359. The next prime is 42278399. The reversal of 42278391 is 19387224.

It is not a de Polignac number, because 42278391 - 2⁵ = 42278359 is a prime.

It is a Duffinian number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42278399) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2348791 + ... + 2348808.

Almost surely, 2^42278391 is an apocalyptic number.

42278391 is a deficient number, since it is larger than the sum of its proper divisors (18790409).

42278391 is a wasteful number, since it uses less digits than its factorization.

42278391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4697605 (or 4697602 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 42278391 is about 6502.1835563140. The cubic root of 42278391 is about 348.3689853596.

The spelling of 42278391 in words is "forty-two million, two hundred seventy-eight thousand, three hundred ninety-one".