42161857 has 4 divisors (see below), whose sum is σ = 42175060. Its totient is φ = 42148656.

The previous prime is 42161851. The next prime is 42161869. The reversal of 42161857 is 75816124.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 16719921 + 25441936 = 4089^2 + 5044^2 .

It is a cyclic number.

It is not a de Polignac number, because 42161857 - 2³ = 42161849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42161851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1519 + ... + 9307.

It is an arithmetic number, because the mean of its divisors is an integer number (10543765).

Almost surely, 2^42161857 is an apocalyptic number.

It is an amenable number.

42161857 is a deficient number, since it is larger than the sum of its proper divisors (13203).

42161857 is an equidigital number, since it uses as much as digits as its factorization.

42161857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13202.

The product of its digits is 13440, while the sum is 34.

The square root of 42161857 is about 6493.2162292657. The cubic root of 42161857 is about 348.0486153291.

The spelling of 42161857 in words is "forty-two million, one hundred sixty-one thousand, eight hundred fifty-seven".