42018181 has 4 divisors (see below), whose sum is σ = 42995392. Its totient is φ = 41040972.

The previous prime is 42018173. The next prime is 42018209. The reversal of 42018181 is 18181024.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 42018181 - 2³ = 42018173 is a prime.

It is a super-2 number, since 2×42018181² = 3531055069097522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42018131) 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, 488541 + ... + 488626.

It is an arithmetic number, because the mean of its divisors is an integer number (10748848).

Almost surely, 2^42018181 is an apocalyptic number.

It is an amenable number.

42018181 is a deficient number, since it is larger than the sum of its proper divisors (977211).

42018181 is an equidigital number, since it uses as much as digits as its factorization.

42018181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 977210.

The product of its (nonzero) digits is 512, while the sum is 25.

The square root of 42018181 is about 6482.1432412436. The cubic root of 42018181 is about 347.6528141106.

The spelling of 42018181 in words is "forty-two million, eighteen thousand, one hundred eighty-one".