42168581 has 32 divisors (see below), whose sum is σ = 56582400. Its totient is φ = 30518208.

The previous prime is 42168563. The next prime is 42168601. The reversal of 42168581 is 18586124.

It is a de Polignac number, because none of the positive numbers 2^k-42168581 is a prime.

It is a super-2 number, since 2×42168581² = 3556378447107122, which contains 22 as substring.

It is a taxicab number since it can be written as a sum of two cubes in more than one way. Here 42168581 = 29³ + 348³ = 261³ + 290³.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42168521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1454075 + ... + 1454103.

It is an arithmetic number, because the mean of its divisors is an integer number (1768200).

Almost surely, 2^42168581 is an apocalyptic number.

It is an amenable number.

42168581 is a deficient number, since it is larger than the sum of its proper divisors (14413819).

42168581 is an equidigital number, since it uses as much as digits as its factorization.

42168581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126 (or 68 counting only the distinct ones).

The product of its digits is 15360, while the sum is 35.

The square root of 42168581 is about 6493.7339797685. The cubic root of 42168581 is about 348.0671166844.

The spelling of 42168581 in words is "forty-two million, one hundred sixty-eight thousand, five hundred eighty-one".