31998000031 has 2 divisors, whose sum is σ = 31998000032. Its totient is φ = 31998000030.

The previous prime is 31998000029. The next prime is 31998000053. The reversal of 31998000031 is 13000089913.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31998000031 - 2¹ = 31998000029 is a prime.

It is a super-2 number, since 2×31998000031² (a number of 22 digits) contains 22 as substring.

Together with 31998000029, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31998000011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15999000015 + 15999000016.

It is an arithmetic number, because the mean of its divisors is an integer number (15999000016).

Almost surely, 2^31998000031 is an apocalyptic number.

31998000031 is the 79998-th centered decagonal number.

31998000031 is a deficient number, since it is larger than the sum of its proper divisors (1).

31998000031 is an equidigital number, since it uses as much as digits as its factorization.

31998000031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5832, while the sum is 34.

Adding to 31998000031 its reverse (13000089913), we get a palindrome (44998089944).

The spelling of 31998000031 in words is "thirty-one billion, nine hundred ninety-eight million, thirty-one", and thus it is an aban number.