42842581 has 4 divisors (see below), whose sum is σ = 43887564. Its totient is φ = 41797600.

The previous prime is 42842573. The next prime is 42842593. The reversal of 42842581 is 18524824.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 24059025 + 18783556 = 4905^2 + 4334^2 .

It is a cyclic number.

It is not a de Polignac number, because 42842581 - 2³ = 42842573 is a prime.

It is a super-2 number, since 2×42842581² = 3670973493483122, 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 (42842531) 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, 522430 + ... + 522511.

It is an arithmetic number, because the mean of its divisors is an integer number (10971891).

Almost surely, 2^42842581 is an apocalyptic number.

42842581 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

42842581 is a deficient number, since it is larger than the sum of its proper divisors (1044983).

42842581 is a wasteful number, since it uses less digits than its factorization.

42842581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1044982.

The product of its digits is 20480, while the sum is 34.

The square root of 42842581 is about 6545.4244323802. The cubic root of 42842581 is about 349.9117627907.

The spelling of 42842581 in words is "forty-two million, eight hundred forty-two thousand, five hundred eighty-one".