42665391 has 24 divisors (see below), whose sum is σ = 65235456. Its totient is φ = 26814480.

The previous prime is 42665383. The next prime is 42665411. The reversal of 42665391 is 19356624.

It is a happy number.

42665391 is a `hidden beast` number, since 4 + 266 + 5 + 391 = 666.

42665391 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 42665391 - 2³ = 42665383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42665321) 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 23 ways as a sum of consecutive naturals, for example, 13246 + ... + 16148.

It is an arithmetic number, because the mean of its divisors is an integer number (2718144).

Almost surely, 2^42665391 is an apocalyptic number.

42665391 is a deficient number, since it is larger than the sum of its proper divisors (22570065).

42665391 is a wasteful number, since it uses less digits than its factorization.

42665391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3003 (or 3000 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

The square root of 42665391 is about 6531.8749988039. The cubic root of 42665391 is about 349.4287033677.

The spelling of 42665391 in words is "forty-two million, six hundred sixty-five thousand, three hundred ninety-one".