42778317 has 4 divisors (see below), whose sum is σ = 57037760. Its totient is φ = 28518876.

The previous prime is 42778303. The next prime is 42778349. The reversal of 42778317 is 71387724.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 42778317 - 2⁷ = 42778189 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 (42778217) 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, 7129717 + ... + 7129722.

It is an arithmetic number, because the mean of its divisors is an integer number (14259440).

Almost surely, 2^42778317 is an apocalyptic number.

It is an amenable number.

42778317 is a deficient number, since it is larger than the sum of its proper divisors (14259443).

42778317 is a wasteful number, since it uses less digits than its factorization.

42778317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14259442.

The product of its digits is 65856, while the sum is 39.

The square root of 42778317 is about 6540.5135119500. The cubic root of 42778317 is about 349.7367190082.

The spelling of 42778317 in words is "forty-two million, seven hundred seventy-eight thousand, three hundred seventeen".