21221102249 has 2 divisors, whose sum is σ = 21221102250. Its totient is φ = 21221102248.

The previous prime is 21221102209. The next prime is 21221102281. The reversal of 21221102249 is 94220112212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17277262249 + 3943840000 = 131443^2 + 62800^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21221102249 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21221102209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610551124 + 10610551125.

It is an arithmetic number, because the mean of its divisors is an integer number (10610551125).

Almost surely, 2^21221102249 is an apocalyptic number.

It is an amenable number.

21221102249 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221102249 is an equidigital number, since it uses as much as digits as its factorization.

21221102249 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 26.

The spelling of 21221102249 in words is "twenty-one billion, two hundred twenty-one million, one hundred two thousand, two hundred forty-nine".