42240031 has 2 divisors, whose sum is σ = 42240032. Its totient is φ = 42240030.

The previous prime is 42240017. The next prime is 42240041. The reversal of 42240031 is 13004224.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42240031 is a prime.

It is a super-2 number, since 2×42240031² = 3568440437761922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 42239987 and 42240014.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42240041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21120015 + 21120016.

It is an arithmetic number, because the mean of its divisors is an integer number (21120016).

Almost surely, 2^42240031 is an apocalyptic number.

42240031 is a deficient number, since it is larger than the sum of its proper divisors (1).

42240031 is an equidigital number, since it uses as much as digits as its factorization.

42240031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 42240031 is about 6499.2331086060. The cubic root of 42240031 is about 348.2635928440.

Adding to 42240031 its reverse (13004224), we get a palindrome (55244255).

The spelling of 42240031 in words is "forty-two million, two hundred forty thousand, thirty-one".