42005631 has 8 divisors (see below), whose sum is σ = 56449024. Its totient is φ = 27783000.

The previous prime is 42005629. The next prime is 42005641. The reversal of 42005631 is 13650024.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 42005631 - 2¹ = 42005629 is a prime.

It is a super-2 number, since 2×42005631² = 3528946071416322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42005598 and 42005607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42005641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54745 + ... + 55506.

It is an arithmetic number, because the mean of its divisors is an integer number (7056128).

Almost surely, 2^42005631 is an apocalyptic number.

42005631 is a deficient number, since it is larger than the sum of its proper divisors (14443393).

42005631 is a wasteful number, since it uses less digits than its factorization.

42005631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110381.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 42005631 is about 6481.1751249291. The cubic root of 42005631 is about 347.6181983231.

Adding to 42005631 its reverse (13650024), we get a palindrome (55655655).

The spelling of 42005631 in words is "forty-two million, five thousand, six hundred thirty-one".