31000220231 has 2 divisors, whose sum is σ = 31000220232. Its totient is φ = 31000220230.

The previous prime is 31000220197. The next prime is 31000220233. The reversal of 31000220231 is 13202200013.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (13202200013) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31000220231 is a prime.

It is a super-2 number, since 2×31000220231² (a number of 22 digits) contains 22 as substring.

Together with 31000220233, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31000220233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15500110115 + 15500110116.

It is an arithmetic number, because the mean of its divisors is an integer number (15500110116).

Almost surely, 2^31000220231 is an apocalyptic number.

31000220231 is a deficient number, since it is larger than the sum of its proper divisors (1).

31000220231 is an equidigital number, since it uses as much as digits as its factorization.

31000220231 is an odious number, because the sum of its binary digits is odd.

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

Adding to 31000220231 its reverse (13202200013), we get a palindrome (44202420244).

The spelling of 31000220231 in words is "thirty-one billion, two hundred twenty thousand, two hundred thirty-one".