221012129981 has 2 divisors, whose sum is σ = 221012129982. Its totient is φ = 221012129980.

The previous prime is 221012129963. The next prime is 221012130013. The reversal of 221012129981 is 189921210122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 220556093956 + 456036025 = 469634^2 + 21355^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221012129981 is a prime.

It is a super-2 number, since 2×221012129981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221012129081) 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, 110506064990 + 110506064991.

It is an arithmetic number, because the mean of its divisors is an integer number (110506064991).

Almost surely, 2^221012129981 is an apocalyptic number.

It is an amenable number.

221012129981 is a deficient number, since it is larger than the sum of its proper divisors (1).

221012129981 is an equidigital number, since it uses as much as digits as its factorization.

221012129981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 38.

The spelling of 221012129981 in words is "two hundred twenty-one billion, twelve million, one hundred twenty-nine thousand, nine hundred eighty-one".