21220220941 has 2 divisors, whose sum is σ = 21220220942. Its totient is φ = 21220220940.

The previous prime is 21220220939. The next prime is 21220221031. The reversal of 21220220941 is 14902202212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14875461225 + 6344759716 = 121965^2 + 79654^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220220941 - 2¹ = 21220220939 is a prime.

Together with 21220220939, 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 (21220220341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610110470 + 10610110471.

It is an arithmetic number, because the mean of its divisors is an integer number (10610110471).

Almost surely, 2^21220220941 is an apocalyptic number.

It is an amenable number.

21220220941 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220220941 is an equidigital number, since it uses as much as digits as its factorization.

21220220941 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 25.

The spelling of 21220220941 in words is "twenty-one billion, two hundred twenty million, two hundred twenty thousand, nine hundred forty-one".