42815709 has 20 divisors (see below), whose sum is σ = 64778560. Its totient is φ = 28178280.

The previous prime is 42815701. The next prime is 42815711. The reversal of 42815709 is 90751824.

42815709 is a `hidden beast` number, since 4 + 2 + 81 + 570 + 9 = 666.

42815709 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 42815709 - 2³ = 42815701 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 (42815701) 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 19 ways as a sum of consecutive naturals, for example, 3054 + ... + 9744.

It is an arithmetic number, because the mean of its divisors is an integer number (3238928).

Almost surely, 2^42815709 is an apocalyptic number.

It is an amenable number.

42815709 is a deficient number, since it is larger than the sum of its proper divisors (21962851).

42815709 is an equidigital number, since it uses as much as digits as its factorization.

42815709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6782 (or 6773 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 42815709 is about 6543.3713787313. The cubic root of 42815709 is about 349.8385895189.

The spelling of 42815709 in words is "forty-two million, eight hundred fifteen thousand, seven hundred nine".