42072181 has 4 divisors (see below), whose sum is σ = 42700192. Its totient is φ = 41444172.

The previous prime is 42072157. The next prime is 42072193. The reversal of 42072181 is 18127024.

It is a happy number.

42072181 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 42072181 - 2²¹ = 39975029 is a prime.

It is a super-2 number, since 2×42072181² = 3540136828193522, 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 (42072281) 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 3 ways as a sum of consecutive naturals, for example, 313905 + ... + 314038.

It is an arithmetic number, because the mean of its divisors is an integer number (10675048).

Almost surely, 2^42072181 is an apocalyptic number.

It is an amenable number.

42072181 is a deficient number, since it is larger than the sum of its proper divisors (628011).

42072181 is an equidigital number, since it uses as much as digits as its factorization.

42072181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 628010.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 42072181 is about 6486.3071928486. The cubic root of 42072181 is about 347.8016799511.

The spelling of 42072181 in words is "forty-two million, seventy-two thousand, one hundred eighty-one".