42665821 has 8 divisors (see below), whose sum is σ = 46720800. Its totient is φ = 38640240.

The previous prime is 42665807. The next prime is 42665867. The reversal of 42665821 is 12856624.

42665821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 42665821 - 2⁹ = 42665309 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 (42665891) 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, 4251 + ... + 10168.

It is an arithmetic number, because the mean of its divisors is an integer number (5840100).

Almost surely, 2^42665821 is an apocalyptic number.

It is an amenable number.

42665821 is a deficient number, since it is larger than the sum of its proper divisors (4054979).

42665821 is a wasteful number, since it uses less digits than its factorization.

42665821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14699.

The product of its digits is 23040, while the sum is 34.

The square root of 42665821 is about 6531.9079142315. The cubic root of 42665821 is about 349.4298772609.

The spelling of 42665821 in words is "forty-two million, six hundred sixty-five thousand, eight hundred twenty-one".