42171831 has 24 divisors (see below), whose sum is σ = 67005120. Its totient is φ = 25396416.

The previous prime is 42171809. The next prime is 42171853. The reversal of 42171831 is 13817124.

It is an interprime number because it is at equal distance from previous prime (42171809) and next prime (42171853).

It is not a de Polignac number, because 42171831 - 2⁹ = 42171319 is a prime.

It is a super-2 number, since 2×42171831² = 3556926659785122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 42171795 and 42171804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42171131) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1665 + ... + 9333.

It is an arithmetic number, because the mean of its divisors is an integer number (2791880).

Almost surely, 2^42171831 is an apocalyptic number.

42171831 is a deficient number, since it is larger than the sum of its proper divisors (24833289).

42171831 is a wasteful number, since it uses less digits than its factorization.

42171831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7735 (or 7732 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 42171831 is about 6493.9842161804. The cubic root of 42171831 is about 348.0760584845.

Adding to 42171831 its reverse (13817124), we get a palindrome (55988955).

The spelling of 42171831 in words is "forty-two million, one hundred seventy-one thousand, eight hundred thirty-one".