42005523 has 16 divisors (see below), whose sum is σ = 67377920. Its totient is φ = 22739616.

The previous prime is 42005519. The next prime is 42005533. The reversal of 42005523 is 32550024.

It is not a de Polignac number, because 42005523 - 2² = 42005519 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

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 42005523.

It is not an unprimeable number, because it can be changed into a prime (42005503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52240 + ... + 53037.

It is an arithmetic number, because the mean of its divisors is an integer number (4211120).

Almost surely, 2^42005523 is an apocalyptic number.

42005523 is a deficient number, since it is larger than the sum of its proper divisors (25372397).

42005523 is a wasteful number, since it uses less digits than its factorization.

42005523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105306.

The product of its (nonzero) digits is 1200, while the sum is 21.

The square root of 42005523 is about 6481.1667931014. The cubic root of 42005523 is about 347.6179004043.

Adding to 42005523 its reverse (32550024), we get a palindrome (74555547).

The spelling of 42005523 in words is "forty-two million, five thousand, five hundred twenty-three".