31543563281 has 2 divisors, whose sum is σ = 31543563282. Its totient is φ = 31543563280.

The previous prime is 31543563253. The next prime is 31543563287. The reversal of 31543563281 is 18236534513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26696618881 + 4846944400 = 163391^2 + 69620^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31543563281 is a prime.

It is a super-2 number, since 2×31543563281² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31543563287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15771781640 + 15771781641.

It is an arithmetic number, because the mean of its divisors is an integer number (15771781641).

Almost surely, 2^31543563281 is an apocalyptic number.

It is an amenable number.

31543563281 is a deficient number, since it is larger than the sum of its proper divisors (1).

31543563281 is an equidigital number, since it uses as much as digits as its factorization.

31543563281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 259200, while the sum is 41.

The spelling of 31543563281 in words is "thirty-one billion, five hundred forty-three million, five hundred sixty-three thousand, two hundred eighty-one".