42940809 has 12 divisors (see below), whose sum is σ = 62723700. Its totient is φ = 28305024.

The previous prime is 42940721. The next prime is 42940823. The reversal of 42940809 is 90804924.

It is a happy number.

42940809 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 2 ways, for example, as 3250809 + 39690000 = 1803^2 + 6300^2 .

It is not a de Polignac number, because 42940809 - 2¹¹ = 42938761 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (42940109) 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 11 ways as a sum of consecutive naturals, for example, 26004 + ... + 27605.

It is an arithmetic number, because the mean of its divisors is an integer number (5226975).

Almost surely, 2^42940809 is an apocalyptic number.

It is an amenable number.

42940809 is a deficient number, since it is larger than the sum of its proper divisors (19782891).

42940809 is a wasteful number, since it uses less digits than its factorization.

42940809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53704 (or 53701 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 42940809 is about 6552.9236986249. The cubic root of 42940809 is about 350.1789805674.

The spelling of 42940809 in words is "forty-two million, nine hundred forty thousand, eight hundred nine".