42978689 has 8 divisors (see below), whose sum is σ = 46338600. Its totient is φ = 39626496.

The previous prime is 42978659. The next prime is 42978721. The reversal of 42978689 is 98687924.

42978689 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 22800625 + 20178064 = 4775^2 + 4492^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 42978689 - 2¹² = 42974593 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 42978689.

It is not an unprimeable number, because it can be changed into a prime (42978659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15587 + ... + 18135.

It is an arithmetic number, because the mean of its divisors is an integer number (5792325).

Almost surely, 2^42978689 is an apocalyptic number.

It is an amenable number.

42978689 is a deficient number, since it is larger than the sum of its proper divisors (3359911).

42978689 is a wasteful number, since it uses less digits than its factorization.

42978689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3859.

The product of its digits is 1741824, while the sum is 53.

The square root of 42978689 is about 6555.8133744029. The cubic root of 42978689 is about 350.2819197956.

The spelling of 42978689 in words is "forty-two million, nine hundred seventy-eight thousand, six hundred eighty-nine".