31240031 has 2 divisors, whose sum is σ = 31240032. Its totient is φ = 31240030.

The previous prime is 31240021. The next prime is 31240043. The reversal of 31240031 is 13004213.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31240031 is a prime.

It is a super-2 number, since 2×31240031² = 1951879073761922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31239988 and 31240015.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31240021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15620015 + 15620016.

It is an arithmetic number, because the mean of its divisors is an integer number (15620016).

Almost surely, 2^31240031 is an apocalyptic number.

31240031 is a deficient number, since it is larger than the sum of its proper divisors (1).

31240031 is an equidigital number, since it uses as much as digits as its factorization.

31240031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 31240031 is about 5589.2782181602. The cubic root of 31240031 is about 314.9467651703.

Adding to 31240031 its reverse (13004213), we get a palindrome (44244244).

The spelling of 31240031 in words is "thirty-one million, two hundred forty thousand, thirty-one".