42805531 has 4 divisors (see below), whose sum is σ = 42910600. Its totient is φ = 42700464.

The previous prime is 42805487. The next prime is 42805561. The reversal of 42805531 is 13550824.

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

It is a cyclic number.

It is not a de Polignac number, because 42805531 - 2⁹ = 42805019 is a prime.

It is a super-2 number, since 2×42805531² = 3664626968383922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42805531.

It is not an unprimeable number, because it can be changed into a prime (42805561) 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, 51921 + ... + 52738.

It is an arithmetic number, because the mean of its divisors is an integer number (10727650).

Almost surely, 2^42805531 is an apocalyptic number.

42805531 is a deficient number, since it is larger than the sum of its proper divisors (105069).

42805531 is a wasteful number, since it uses less digits than its factorization.

42805531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105068.

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 42805531 is about 6542.5935988719. The cubic root of 42805531 is about 349.8108665217.

The spelling of 42805531 in words is "forty-two million, eight hundred five thousand, five hundred thirty-one".