221012321081 has 2 divisors, whose sum is σ = 221012321082. Its totient is φ = 221012321080.

The previous prime is 221012321069. The next prime is 221012321099. The reversal of 221012321081 is 180123210122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 206607520681 + 14404800400 = 454541^2 + 120020^2 .

It is a cyclic number.

It is not a de Polignac number, because 221012321081 - 2²² = 221008126777 is a prime.

It is a super-3 number, since 3×221012321081³ (a number of 35 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (221012321011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110506160540 + 110506160541.

It is an arithmetic number, because the mean of its divisors is an integer number (110506160541).

Almost surely, 2^221012321081 is an apocalyptic number.

It is an amenable number.

221012321081 is a deficient number, since it is larger than the sum of its proper divisors (1).

221012321081 is an equidigital number, since it uses as much as digits as its factorization.

221012321081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 23.

The spelling of 221012321081 in words is "two hundred twenty-one billion, twelve million, three hundred twenty-one thousand, eighty-one".