21012221199941 has 2 divisors, whose sum is σ = 21012221199942. Its totient is φ = 21012221199940.

The previous prime is 21012221199901. The next prime is 21012221199979. The reversal of 21012221199941 is 14999112221012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20980485558916 + 31735641025 = 4580446^2 + 178145^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21012221199941 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21012221199892 and 21012221199901.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012221199901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506110599970 + 10506110599971.

It is an arithmetic number, because the mean of its divisors is an integer number (10506110599971).

Almost surely, 2^{21012221199941} is an apocalyptic number.

It is an amenable number.

21012221199941 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012221199941 is an equidigital number, since it uses as much as digits as its factorization.

21012221199941 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 44.

The spelling of 21012221199941 in words is "twenty-one trillion, twelve billion, two hundred twenty-one million, one hundred ninety-nine thousand, nine hundred forty-one".