42085891 has 4 divisors (see below), whose sum is σ = 42354112. Its totient is φ = 41817672.

The previous prime is 42085877. The next prime is 42085919. The reversal of 42085891 is 19858024.

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 42085891 - 2¹³ = 42077699 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42085891.

It is not an unprimeable number, because it can be changed into a prime (42085801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 133875 + ... + 134188.

It is an arithmetic number, because the mean of its divisors is an integer number (10588528).

Almost surely, 2^42085891 is an apocalyptic number.

42085891 is a deficient number, since it is larger than the sum of its proper divisors (268221).

42085891 is a wasteful number, since it uses less digits than its factorization.

42085891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268220.

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 42085891 is about 6487.3639484771. The cubic root of 42085891 is about 347.8394550562.

The spelling of 42085891 in words is "forty-two million, eighty-five thousand, eight hundred ninety-one".