42878729 has 4 divisors (see below), whose sum is σ = 43094400. Its totient is φ = 42663060.

The previous prime is 42878723. The next prime is 42878761. The reversal of 42878729 is 92787824.

It is a happy number.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42878729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42878723) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 107537 + ... + 107934.

It is an arithmetic number, because the mean of its divisors is an integer number (10773600).

Almost surely, 2^42878729 is an apocalyptic number.

It is an amenable number.

42878729 is a deficient number, since it is larger than the sum of its proper divisors (215671).

42878729 is a wasteful number, since it uses less digits than its factorization.

42878729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215670.

The product of its digits is 451584, while the sum is 47.

The square root of 42878729 is about 6548.1851684264. The cubic root of 42878729 is about 350.0101466446.

The spelling of 42878729 in words is "forty-two million, eight hundred seventy-eight thousand, seven hundred twenty-nine".