21110353217 has 2 divisors, whose sum is σ = 21110353218. Its totient is φ = 21110353216.

The previous prime is 21110353213. The next prime is 21110353241. The reversal of 21110353217 is 71235301112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20883429121 + 226924096 = 144511^2 + 15064^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110353217 - 2² = 21110353213 is a prime.

It is not a weakly prime, because it can be changed into another prime (21110353213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555176608 + 10555176609.

It is an arithmetic number, because the mean of its divisors is an integer number (10555176609).

Almost surely, 2^21110353217 is an apocalyptic number.

It is an amenable number.

21110353217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110353217 is an equidigital number, since it uses as much as digits as its factorization.

21110353217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1260, while the sum is 26.

Adding to 21110353217 its reverse (71235301112), we get a palindrome (92345654329).

The spelling of 21110353217 in words is "twenty-one billion, one hundred ten million, three hundred fifty-three thousand, two hundred seventeen".