31001023221281 has 2 divisors, whose sum is σ = 31001023221282. Its totient is φ = 31001023221280.

The previous prime is 31001023221271. The next prime is 31001023221347. The reversal of 31001023221281 is 18212232010013.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30727066240000 + 273956981281 = 5543200^2 + 523409^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31001023221281 is a prime.

It is a super-2 number, since 2×31001023221281² (a number of 28 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31001023221281.

It is not a weakly prime, because it can be changed into another prime (31001023221211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15500511610640 + 15500511610641.

It is an arithmetic number, because the mean of its divisors is an integer number (15500511610641).

Almost surely, 2^{31001023221281} is an apocalyptic number.

It is an amenable number.

31001023221281 is a deficient number, since it is larger than the sum of its proper divisors (1).

31001023221281 is an equidigital number, since it uses as much as digits as its factorization.

31001023221281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 26.

Adding to 31001023221281 its reverse (18212232010013), we get a palindrome (49213255231294).

The spelling of 31001023221281 in words is "thirty-one trillion, one billion, twenty-three million, two hundred twenty-one thousand, two hundred eighty-one".