42640999 has 4 divisors (see below), whose sum is σ = 42696936. Its totient is φ = 42585064.

The previous prime is 42640957. The next prime is 42641009. The reversal of 42640999 is 99904624.

42640999 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 42640999 - 2¹¹ = 42638951 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 (42640099) 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 3 ways as a sum of consecutive naturals, for example, 26809 + ... + 28354.

It is an arithmetic number, because the mean of its divisors is an integer number (10674234).

Almost surely, 2^42640999 is an apocalyptic number.

42640999 is a deficient number, since it is larger than the sum of its proper divisors (55937).

42640999 is an equidigital number, since it uses as much as digits as its factorization.

42640999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55936.

The product of its (nonzero) digits is 139968, while the sum is 43.

The square root of 42640999 is about 6530.0075803938. The cubic root of 42640999 is about 349.3621006755.

The spelling of 42640999 in words is "forty-two million, six hundred forty thousand, nine hundred ninety-nine".