42640857 has 16 divisors (see below), whose sum is σ = 72196480. Its totient is φ = 24366096.

The previous prime is 42640849. The next prime is 42640859. The reversal of 42640857 is 75804624.

42640857 is a `hidden beast` number, since 4 + 2 + 640 + 8 + 5 + 7 = 666.

42640857 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 42640857 - 2³ = 42640849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42640859) 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 15 ways as a sum of consecutive naturals, for example, 112618 + ... + 112995.

It is an arithmetic number, because the mean of its divisors is an integer number (4512280).

Almost surely, 2^42640857 is an apocalyptic number.

It is an amenable number.

42640857 is a deficient number, since it is larger than the sum of its proper divisors (29555623).

42640857 is a wasteful number, since it uses less digits than its factorization.

42640857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225629 (or 225623 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 42640857 is about 6529.9967075030. The cubic root of 42640857 is about 349.3617128682.

The spelling of 42640857 in words is "forty-two million, six hundred forty thousand, eight hundred fifty-seven".