221311102981 has 2 divisors, whose sum is σ = 221311102982. Its totient is φ = 221311102980.

The previous prime is 221311102979. The next prime is 221311103089. The reversal of 221311102981 is 189201113122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 179296352356 + 42014750625 = 423434^2 + 204975^2 .

It is a cyclic number.

It is not a de Polignac number, because 221311102981 - 2¹ = 221311102979 is a prime.

It is a super-2 number, since 2×221311102981² (a number of 23 digits) contains 22 as substring.

Together with 221311102979, 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 (221311102931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110655551490 + 110655551491.

It is an arithmetic number, because the mean of its divisors is an integer number (110655551491).

Almost surely, 2^221311102981 is an apocalyptic number.

It is an amenable number.

221311102981 is a deficient number, since it is larger than the sum of its proper divisors (1).

221311102981 is an equidigital number, since it uses as much as digits as its factorization.

221311102981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 31.

The spelling of 221311102981 in words is "two hundred twenty-one billion, three hundred eleven million, one hundred two thousand, nine hundred eighty-one".